From f8383c3417e0bc4addc8427f0acff32b5344455b Mon Sep 17 00:00:00 2001
From: Jacek Caban <jacek@codeweavers.com>
Date: Mon, 25 Jun 2012 14:08:38 +0200
Subject: [PATCH] jscript: Don't use DISPPARAMS for internal arguments.

---
 dlls/jscript/activex.c  |   8 +-
 dlls/jscript/array.c    | 107 ++++++++--------
 dlls/jscript/bool.c     |  12 +-
 dlls/jscript/date.c     | 277 ++++++++++++++++++++--------------------
 dlls/jscript/dispex.c   | 224 ++++++++++++++++----------------
 dlls/jscript/engine.c   |  47 ++-----
 dlls/jscript/error.c    |  48 +++----
 dlls/jscript/function.c | 154 +++++++++-------------
 dlls/jscript/global.c   | 168 ++++++++++++------------
 dlls/jscript/jscript.h  |  16 +--
 dlls/jscript/jsutils.c  |   5 +-
 dlls/jscript/math.c     | 116 ++++++++---------
 dlls/jscript/number.c   |  40 +++---
 dlls/jscript/object.c   |  32 ++---
 dlls/jscript/regexp.c   |  49 ++++---
 dlls/jscript/string.c   | 244 +++++++++++++++++------------------
 dlls/jscript/vbarray.c  |  42 +++---
 17 files changed, 744 insertions(+), 845 deletions(-)

diff --git a/dlls/jscript/activex.c b/dlls/jscript/activex.c
index 8e2eed4e3c8..16b6b4213b4 100644
--- a/dlls/jscript/activex.c
+++ b/dlls/jscript/activex.c
@@ -138,7 +138,7 @@ static IUnknown *create_activex_object(script_ctx_t *ctx, const WCHAR *progid)
     return obj;
 }
 
-static HRESULT ActiveXObject_value(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT ActiveXObject_value(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     IDispatch *disp;
@@ -159,12 +159,12 @@ static HRESULT ActiveXObject_value(script_ctx_t *ctx, vdisp_t *jsthis, WORD flag
         return E_NOTIMPL;
     }
 
-    if(arg_cnt(dp) != 1) {
-        FIXME("unsupported arg_cnt %d\n", arg_cnt(dp));
+    if(argc != 1) {
+        FIXME("unsupported argc %d\n", argc);
         return E_NOTIMPL;
     }
 
-    hres = to_string(ctx, get_arg(dp,0), ei, &progid);
+    hres = to_string(ctx, argv, ei, &progid);
     if(FAILED(hres))
         return hres;
 
diff --git a/dlls/jscript/array.c b/dlls/jscript/array.c
index 139b04d6388..5004eb58788 100644
--- a/dlls/jscript/array.c
+++ b/dlls/jscript/array.c
@@ -116,7 +116,7 @@ static WCHAR *idx_to_str(DWORD idx, WCHAR *ptr)
     return ptr+1;
 }
 
-static HRESULT Array_length(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Array_length(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     ArrayInstance *This = array_from_vdisp(jsthis);
@@ -132,7 +132,7 @@ static HRESULT Array_length(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISP
         DWORD i;
         HRESULT hres;
 
-        hres = to_number(ctx, get_arg(dp, 0), ei, &len);
+        hres = to_number(ctx, argv, ei, &len);
         if(FAILED(hres))
             return hres;
 
@@ -201,7 +201,7 @@ static HRESULT concat_obj(jsdisp_t *array, IDispatch *obj, DWORD *len, jsexcept_
     return jsdisp_propput_idx(array, (*len)++, &var, ei);
 }
 
-static HRESULT Array_concat(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Array_concat(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     jsdisp_t *ret;
@@ -219,8 +219,8 @@ static HRESULT Array_concat(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISP
         VARIANT *arg;
         DWORD i;
 
-        for(i=0; i < arg_cnt(dp); i++) {
-            arg = get_arg(dp, i);
+        for(i=0; i < argc; i++) {
+            arg = argv+i;
             if(V_VT(arg) == VT_DISPATCH)
                 hres = concat_obj(ret, V_DISPATCH(arg), &len, ei);
             else
@@ -340,7 +340,7 @@ static HRESULT array_join(script_ctx_t *ctx, jsdisp_t *array, DWORD length, cons
 }
 
 /* ECMA-262 3rd Edition    15.4.4.5 */
-static HRESULT Array_join(script_ctx_t *ctx, vdisp_t *vthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Array_join(script_ctx_t *ctx, vdisp_t *vthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     jsdisp_t *jsthis;
@@ -353,10 +353,10 @@ static HRESULT Array_join(script_ctx_t *ctx, vdisp_t *vthis, WORD flags, DISPPAR
     if(FAILED(hres))
         return hres;
 
-    if(arg_cnt(dp)) {
+    if(argc) {
         BSTR sep;
 
-        hres = to_string(ctx, get_arg(dp,0), ei, &sep);
+        hres = to_string(ctx, argv, ei, &sep);
         if(FAILED(hres))
             return hres;
 
@@ -370,7 +370,7 @@ static HRESULT Array_join(script_ctx_t *ctx, vdisp_t *vthis, WORD flags, DISPPAR
     return hres;
 }
 
-static HRESULT Array_pop(script_ctx_t *ctx, vdisp_t *vthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Array_pop(script_ctx_t *ctx, vdisp_t *vthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     jsdisp_t *jsthis;
@@ -421,12 +421,12 @@ static HRESULT Array_pop(script_ctx_t *ctx, vdisp_t *vthis, WORD flags, DISPPARA
 }
 
 /* ECMA-262 3rd Edition    15.4.4.7 */
-static HRESULT Array_push(script_ctx_t *ctx, vdisp_t *vthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Array_push(script_ctx_t *ctx, vdisp_t *vthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     jsdisp_t *jsthis;
     DWORD length = 0;
-    int i, n;
+    unsigned i;
     HRESULT hres;
 
     TRACE("\n");
@@ -435,23 +435,22 @@ static HRESULT Array_push(script_ctx_t *ctx, vdisp_t *vthis, WORD flags, DISPPAR
     if(FAILED(hres))
         return hres;
 
-    n = arg_cnt(dp);
-    for(i=0; i < n; i++) {
-        hres = jsdisp_propput_idx(jsthis, length+i, get_arg(dp, i), ei);
+    for(i=0; i < argc; i++) {
+        hres = jsdisp_propput_idx(jsthis, length+i, argv+i, ei);
         if(FAILED(hres))
             return hres;
     }
 
-    hres = set_length(jsthis, ei, length+n);
+    hres = set_length(jsthis, ei, length+argc);
     if(FAILED(hres))
         return hres;
 
     if(retv)
-        num_set_int(retv, length+n);
+        num_set_int(retv, length+argc);
     return S_OK;
 }
 
-static HRESULT Array_reverse(script_ctx_t *ctx, vdisp_t *vthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Array_reverse(script_ctx_t *ctx, vdisp_t *vthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     jsdisp_t *jsthis;
@@ -509,7 +508,7 @@ static HRESULT Array_reverse(script_ctx_t *ctx, vdisp_t *vthis, WORD flags, DISP
 }
 
 /* ECMA-262 3rd Edition    15.4.4.9 */
-static HRESULT Array_shift(script_ctx_t *ctx, vdisp_t *vthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Array_shift(script_ctx_t *ctx, vdisp_t *vthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     jsdisp_t *jsthis;
@@ -563,7 +562,7 @@ static HRESULT Array_shift(script_ctx_t *ctx, vdisp_t *vthis, WORD flags, DISPPA
 }
 
 /* ECMA-262 3rd Edition    15.4.4.10 */
-static HRESULT Array_slice(script_ctx_t *ctx, vdisp_t *vthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Array_slice(script_ctx_t *ctx, vdisp_t *vthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     jsdisp_t *arr, *jsthis;
@@ -577,8 +576,8 @@ static HRESULT Array_slice(script_ctx_t *ctx, vdisp_t *vthis, WORD flags, DISPPA
     if(FAILED(hres))
         return hres;
 
-    if(arg_cnt(dp)) {
-        hres = to_number(ctx, get_arg(dp, 0), ei, &range);
+    if(argc) {
+        hres = to_number(ctx, argv, ei, &range);
         if(FAILED(hres))
             return hres;
 
@@ -590,8 +589,8 @@ static HRESULT Array_slice(script_ctx_t *ctx, vdisp_t *vthis, WORD flags, DISPPA
     }
     else start = 0;
 
-    if(arg_cnt(dp)>1) {
-        hres = to_number(ctx, get_arg(dp, 1), ei, &range);
+    if(argc > 1) {
+        hres = to_number(ctx, argv+1, ei, &range);
         if(FAILED(hres))
             return hres;
 
@@ -639,14 +638,13 @@ static HRESULT sort_cmp(script_ctx_t *ctx, jsdisp_t *cmp_func, VARIANT *v1, VARI
 
     if(cmp_func) {
         VARIANTARG args[2];
-        DISPPARAMS dp = {args, NULL, 2, 0};
         double n;
         VARIANT res;
 
-        args[0] = *v2;
-        args[1] = *v1;
+        args[0] = *v1;
+        args[1] = *v2;
 
-        hres = jsdisp_call_value(cmp_func, NULL, DISPATCH_METHOD, &dp, &res, ei);
+        hres = jsdisp_call_value(cmp_func, NULL, DISPATCH_METHOD, 2, args, &res, ei);
         if(FAILED(hres))
             return hres;
 
@@ -689,7 +687,7 @@ static HRESULT sort_cmp(script_ctx_t *ctx, jsdisp_t *cmp_func, VARIANT *v1, VARI
 }
 
 /* ECMA-262 3rd Edition    15.4.4.11 */
-static HRESULT Array_sort(script_ctx_t *ctx, vdisp_t *vthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Array_sort(script_ctx_t *ctx, vdisp_t *vthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     jsdisp_t *jsthis, *cmp_func = NULL;
@@ -704,21 +702,19 @@ static HRESULT Array_sort(script_ctx_t *ctx, vdisp_t *vthis, WORD flags, DISPPAR
     if(FAILED(hres))
         return hres;
 
-    if(arg_cnt(dp) > 1) {
-        WARN("invalid arg_cnt %d\n", arg_cnt(dp));
+    if(argc > 1) {
+        WARN("invalid arg_cnt %d\n", argc);
         return E_FAIL;
     }
 
-    if(arg_cnt(dp) == 1) {
-        VARIANT *arg = get_arg(dp, 0);
-
-        if(V_VT(arg) != VT_DISPATCH) {
+    if(argc == 1) {
+        if(V_VT(argv) != VT_DISPATCH) {
             WARN("arg is not dispatch\n");
             return E_FAIL;
         }
 
 
-        cmp_func = iface_to_jsdisp((IUnknown*)V_DISPATCH(arg));
+        cmp_func = iface_to_jsdisp((IUnknown*)V_DISPATCH(argv));
         if(!cmp_func || !is_class(cmp_func, JSCLASS_FUNCTION)) {
             WARN("cmp_func is not a function\n");
             if(cmp_func)
@@ -844,10 +840,10 @@ static HRESULT Array_sort(script_ctx_t *ctx, vdisp_t *vthis, WORD flags, DISPPAR
 }
 
 /* ECMA-262 3rd Edition    15.4.4.12 */
-static HRESULT Array_splice(script_ctx_t *ctx, vdisp_t *vthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Array_splice(script_ctx_t *ctx, vdisp_t *vthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
-    DWORD length, start=0, delete_cnt=0, argc, i, add_args = 0;
+    DWORD length, start=0, delete_cnt=0, i, add_args = 0;
     jsdisp_t *ret_array = NULL, *jsthis;
     VARIANT v;
     double d;
@@ -860,9 +856,8 @@ static HRESULT Array_splice(script_ctx_t *ctx, vdisp_t *vthis, WORD flags, DISPP
     if(FAILED(hres))
         return hres;
 
-    argc = arg_cnt(dp);
-    if(argc >= 1) {
-        hres = to_integer(ctx, get_arg(dp,0), ei, &d);
+    if(argc) {
+        hres = to_integer(ctx, argv, ei, &d);
         if(FAILED(hres))
             return hres;
 
@@ -877,7 +872,7 @@ static HRESULT Array_splice(script_ctx_t *ctx, vdisp_t *vthis, WORD flags, DISPP
     }
 
     if(argc >= 2) {
-        hres = to_integer(ctx, get_arg(dp,1), ei, &d);
+        hres = to_integer(ctx, argv+1, ei, &d);
         if(FAILED(hres))
             return hres;
 
@@ -932,7 +927,7 @@ static HRESULT Array_splice(script_ctx_t *ctx, vdisp_t *vthis, WORD flags, DISPP
     }
 
     for(i=0; SUCCEEDED(hres) && i < add_args; i++)
-        hres = jsdisp_propput_idx(jsthis, start+i, get_arg(dp,i+2), ei);
+        hres = jsdisp_propput_idx(jsthis, start+i, argv+i+2, ei);
 
     if(SUCCEEDED(hres)) {
         num_set_int(&v, length-delete_cnt+add_args);
@@ -951,7 +946,7 @@ static HRESULT Array_splice(script_ctx_t *ctx, vdisp_t *vthis, WORD flags, DISPP
 }
 
 /* ECMA-262 3rd Edition    15.4.4.2 */
-static HRESULT Array_toString(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Array_toString(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     ArrayInstance *array;
@@ -965,7 +960,7 @@ static HRESULT Array_toString(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DI
     return array_join(ctx, &array->dispex, array->length, default_separatorW, retv, ei);
 }
 
-static HRESULT Array_toLocaleString(script_ctx_t *ctx, vdisp_t *vthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Array_toLocaleString(script_ctx_t *ctx, vdisp_t *vthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     FIXME("\n");
@@ -973,12 +968,12 @@ static HRESULT Array_toLocaleString(script_ctx_t *ctx, vdisp_t *vthis, WORD flag
 }
 
 /* ECMA-262 3rd Edition    15.4.4.13 */
-static HRESULT Array_unshift(script_ctx_t *ctx, vdisp_t *vthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Array_unshift(script_ctx_t *ctx, vdisp_t *vthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     jsdisp_t *jsthis;
     WCHAR buf[14], *buf_end, *str;
-    DWORD argc, i, length;
+    DWORD i, length;
     VARIANT var;
     DISPID id;
     HRESULT hres;
@@ -989,7 +984,6 @@ static HRESULT Array_unshift(script_ctx_t *ctx, vdisp_t *vthis, WORD flags, DISP
     if(FAILED(hres))
         return hres;
 
-    argc = arg_cnt(dp);
     if(argc) {
         buf_end = buf + sizeof(buf)/sizeof(WCHAR)-1;
         *buf_end-- = 0;
@@ -1016,7 +1010,7 @@ static HRESULT Array_unshift(script_ctx_t *ctx, vdisp_t *vthis, WORD flags, DISP
     }
 
     for(i=0; i<argc; i++) {
-        hres = jsdisp_propput_idx(jsthis, i, get_arg(dp,i), ei);
+        hres = jsdisp_propput_idx(jsthis, i, argv+i, ei);
         if(FAILED(hres))
             return hres;
     }
@@ -1037,7 +1031,7 @@ static HRESULT Array_unshift(script_ctx_t *ctx, vdisp_t *vthis, WORD flags, DISP
     return S_OK;
 }
 
-static HRESULT Array_value(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Array_value(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     TRACE("\n");
@@ -1106,11 +1100,10 @@ static const builtin_info_t Array_info = {
     Array_on_put
 };
 
-static HRESULT ArrayConstr_value(script_ctx_t *ctx, vdisp_t *vthis, WORD flags, DISPPARAMS *dp,
+static HRESULT ArrayConstr_value(script_ctx_t *ctx, vdisp_t *vthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     jsdisp_t *obj;
-    VARIANT *arg_var;
     DWORD i;
     HRESULT hres;
 
@@ -1119,11 +1112,11 @@ static HRESULT ArrayConstr_value(script_ctx_t *ctx, vdisp_t *vthis, WORD flags,
     switch(flags) {
     case DISPATCH_METHOD:
     case DISPATCH_CONSTRUCT: {
-        if(arg_cnt(dp) == 1 && V_VT((arg_var = get_arg(dp, 0))) == VT_I4) {
-            if(V_I4(arg_var) < 0)
+        if(argc == 1 && V_VT(argv) == VT_I4) {
+            if(V_I4(argv) < 0)
                 return throw_range_error(ctx, ei, JS_E_INVALID_LENGTH, NULL);
 
-            hres = create_array(ctx, V_I4(arg_var), &obj);
+            hres = create_array(ctx, V_I4(argv), &obj);
             if(FAILED(hres))
                 return hres;
 
@@ -1131,12 +1124,12 @@ static HRESULT ArrayConstr_value(script_ctx_t *ctx, vdisp_t *vthis, WORD flags,
             return S_OK;
         }
 
-        hres = create_array(ctx, arg_cnt(dp), &obj);
+        hres = create_array(ctx, argc, &obj);
         if(FAILED(hres))
             return hres;
 
-        for(i=0; i < arg_cnt(dp); i++) {
-            hres = jsdisp_propput_idx(obj, i, get_arg(dp, i), ei);
+        for(i=0; i < argc; i++) {
+            hres = jsdisp_propput_idx(obj, i, argv+i, ei);
             if(FAILED(hres))
                 break;
         }
diff --git a/dlls/jscript/bool.c b/dlls/jscript/bool.c
index 91c969dbdde..6ddcf9e5cf7 100644
--- a/dlls/jscript/bool.c
+++ b/dlls/jscript/bool.c
@@ -38,7 +38,7 @@ static inline BoolInstance *bool_this(vdisp_t *jsthis)
 }
 
 /* ECMA-262 3rd Edition    15.6.4.2 */
-static HRESULT Bool_toString(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Bool_toString(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     BoolInstance *bool;
@@ -68,7 +68,7 @@ static HRESULT Bool_toString(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DIS
 }
 
 /* ECMA-262 3rd Edition    15.6.4.3 */
-static HRESULT Bool_valueOf(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Bool_valueOf(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     BoolInstance *bool;
@@ -86,7 +86,7 @@ static HRESULT Bool_valueOf(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISP
     return S_OK;
 }
 
-static HRESULT Bool_value(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Bool_value(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     TRACE("\n");
@@ -117,14 +117,14 @@ static const builtin_info_t Bool_info = {
     NULL
 };
 
-static HRESULT BoolConstr_value(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT BoolConstr_value(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     HRESULT hres;
     VARIANT_BOOL value = VARIANT_FALSE;
 
-    if(arg_cnt(dp)) {
-        hres = to_boolean(get_arg(dp,0), &value);
+    if(argc) {
+        hres = to_boolean(argv, &value);
         if(FAILED(hres))
             return hres;
     }
diff --git a/dlls/jscript/date.c b/dlls/jscript/date.c
index d5824b72dff..4dad1e29f0b 100644
--- a/dlls/jscript/date.c
+++ b/dlls/jscript/date.c
@@ -602,7 +602,7 @@ static HRESULT dateobj_to_string(DateInstance *date, VARIANT *retv)
     return date_to_string(time, TRUE, offset, retv);
 }
 
-static HRESULT Date_toString(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Date_toString(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     DateInstance *date;
@@ -616,7 +616,7 @@ static HRESULT Date_toString(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DIS
 }
 
 /* ECMA-262 3rd Edition    15.9.1.5 */
-static HRESULT Date_toLocaleString(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Date_toLocaleString(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     static const WCHAR NaNW[] = { 'N','a','N',0 };
@@ -661,7 +661,7 @@ static HRESULT Date_toLocaleString(script_ctx_t *ctx, vdisp_t *jsthis, WORD flag
     return S_OK;
 }
 
-static HRESULT Date_valueOf(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Date_valueOf(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     DateInstance *date;
@@ -780,14 +780,14 @@ static inline HRESULT create_utc_string(script_ctx_t *ctx, vdisp_t *jsthis,
 }
 
 /* ECMA-262 3rd Edition    15.9.5.42 */
-static HRESULT Date_toUTCString(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Date_toUTCString(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     TRACE("\n");
     return create_utc_string(ctx, jsthis, retv, ei);
 }
 
-static HRESULT Date_toGMTString(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Date_toGMTString(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     TRACE("\n");
@@ -892,7 +892,7 @@ static HRESULT dateobj_to_date_string(DateInstance *date, VARIANT *retv)
     return S_OK;
 }
 
-static HRESULT Date_toDateString(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Date_toDateString(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     DateInstance *date;
@@ -904,7 +904,7 @@ static HRESULT Date_toDateString(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags,
 }
 
 /* ECMA-262 3rd Edition    15.9.5.4 */
-static HRESULT Date_toTimeString(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Date_toTimeString(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     static const WCHAR NaNW[] = { 'N','a','N',0 };
@@ -964,7 +964,7 @@ static HRESULT Date_toTimeString(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags,
 }
 
 /* ECMA-262 3rd Edition    15.9.5.6 */
-static HRESULT Date_toLocaleDateString(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Date_toLocaleDateString(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     static const WCHAR NaNW[] = { 'N','a','N',0 };
@@ -1007,7 +1007,7 @@ static HRESULT Date_toLocaleDateString(script_ctx_t *ctx, vdisp_t *jsthis, WORD
 }
 
 /* ECMA-262 3rd Edition    15.9.5.7 */
-static HRESULT Date_toLocaleTimeString(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Date_toLocaleTimeString(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     static const WCHAR NaNW[] = { 'N','a','N',0 };
@@ -1034,7 +1034,7 @@ static HRESULT Date_toLocaleTimeString(script_ctx_t *ctx, vdisp_t *jsthis, WORD
     st = create_systemtime(local_time(date->time, date));
 
     if(st.wYear<1601 || st.wYear>9999)
-        return Date_toTimeString(ctx, jsthis, flags, dp, retv, ei);
+        return Date_toTimeString(ctx, jsthis, flags, argc, argv, retv, ei);
 
     if(retv) {
         len = GetTimeFormatW(ctx->lcid, 0, &st, NULL, NULL, 0);
@@ -1050,7 +1050,7 @@ static HRESULT Date_toLocaleTimeString(script_ctx_t *ctx, vdisp_t *jsthis, WORD
 }
 
 /* ECMA-262 3rd Edition    15.9.5.9 */
-static HRESULT Date_getTime(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Date_getTime(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     DateInstance *date;
@@ -1066,7 +1066,7 @@ static HRESULT Date_getTime(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISP
 }
 
 /* ECMA-262 3rd Edition    15.9.5.10 */
-static HRESULT Date_getFullYear(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Date_getFullYear(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     DateInstance *date;
@@ -1085,7 +1085,7 @@ static HRESULT Date_getFullYear(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags,
 }
 
 /* ECMA-262 3rd Edition    15.9.5.11 */
-static HRESULT Date_getUTCFullYear(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Date_getUTCFullYear(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     DateInstance *date;
@@ -1101,7 +1101,7 @@ static HRESULT Date_getUTCFullYear(script_ctx_t *ctx, vdisp_t *jsthis, WORD flag
 }
 
 /* ECMA-262 3rd Edition    15.9.5.12 */
-static HRESULT Date_getMonth(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Date_getMonth(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     DateInstance *date;
@@ -1120,7 +1120,7 @@ static HRESULT Date_getMonth(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DIS
 }
 
 /* ECMA-262 3rd Edition    15.9.5.13 */
-static HRESULT Date_getUTCMonth(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Date_getUTCMonth(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     DateInstance *date;
@@ -1136,7 +1136,7 @@ static HRESULT Date_getUTCMonth(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags,
 }
 
 /* ECMA-262 3rd Edition    15.9.5.14 */
-static HRESULT Date_getDate(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Date_getDate(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     DateInstance *date;
@@ -1155,7 +1155,7 @@ static HRESULT Date_getDate(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISP
 }
 
 /* ECMA-262 3rd Edition    15.9.5.15 */
-static HRESULT Date_getUTCDate(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Date_getUTCDate(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     DateInstance *date;
@@ -1171,7 +1171,7 @@ static HRESULT Date_getUTCDate(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, D
 }
 
 /* ECMA-262 3rd Edition    15.9.5.16 */
-static HRESULT Date_getDay(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Date_getDay(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     DateInstance *date;
@@ -1190,7 +1190,7 @@ static HRESULT Date_getDay(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPP
 }
 
 /* ECMA-262 3rd Edition    15.9.5.17 */
-static HRESULT Date_getUTCDay(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Date_getUTCDay(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     DateInstance *date;
@@ -1206,7 +1206,7 @@ static HRESULT Date_getUTCDay(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DI
 }
 
 /* ECMA-262 3rd Edition    15.9.5.18 */
-static HRESULT Date_getHours(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Date_getHours(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     DateInstance *date;
@@ -1225,7 +1225,7 @@ static HRESULT Date_getHours(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DIS
 }
 
 /* ECMA-262 3rd Edition    15.9.5.19 */
-static HRESULT Date_getUTCHours(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Date_getUTCHours(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     DateInstance *date;
@@ -1241,7 +1241,7 @@ static HRESULT Date_getUTCHours(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags,
 }
 
 /* ECMA-262 3rd Edition    15.9.5.20 */
-static HRESULT Date_getMinutes(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Date_getMinutes(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     DateInstance *date;
@@ -1260,7 +1260,7 @@ static HRESULT Date_getMinutes(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, D
 }
 
 /* ECMA-262 3rd Edition    15.9.5.21 */
-static HRESULT Date_getUTCMinutes(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Date_getUTCMinutes(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     DateInstance *date;
@@ -1276,7 +1276,7 @@ static HRESULT Date_getUTCMinutes(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags
 }
 
 /* ECMA-262 3rd Edition    15.9.5.22 */
-static HRESULT Date_getSeconds(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Date_getSeconds(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     DateInstance *date;
@@ -1295,7 +1295,7 @@ static HRESULT Date_getSeconds(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, D
 }
 
 /* ECMA-262 3rd Edition    15.9.5.23 */
-static HRESULT Date_getUTCSeconds(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Date_getUTCSeconds(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     DateInstance *date;
@@ -1311,7 +1311,7 @@ static HRESULT Date_getUTCSeconds(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags
 }
 
 /* ECMA-262 3rd Edition    15.9.5.24 */
-static HRESULT Date_getMilliseconds(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Date_getMilliseconds(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     DateInstance *date;
@@ -1330,7 +1330,7 @@ static HRESULT Date_getMilliseconds(script_ctx_t *ctx, vdisp_t *jsthis, WORD fla
 }
 
 /* ECMA-262 3rd Edition    15.9.5.25 */
-static HRESULT Date_getUTCMilliseconds(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Date_getUTCMilliseconds(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     DateInstance *date;
@@ -1346,7 +1346,7 @@ static HRESULT Date_getUTCMilliseconds(script_ctx_t *ctx, vdisp_t *jsthis, WORD
 }
 
 /* ECMA-262 3rd Edition    15.9.5.26 */
-static HRESULT Date_getTimezoneOffset(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Date_getTimezoneOffset(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     DateInstance *date;
@@ -1363,7 +1363,7 @@ static HRESULT Date_getTimezoneOffset(script_ctx_t *ctx, vdisp_t *jsthis, WORD f
 }
 
 /* ECMA-262 3rd Edition    15.9.5.27 */
-static HRESULT Date_setTime(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Date_setTime(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     double n;
@@ -1375,10 +1375,10 @@ static HRESULT Date_setTime(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISP
     if(!(date = date_this(jsthis)))
         return throw_type_error(ctx, ei, JS_E_DATE_EXPECTED, NULL);
 
-    if(!arg_cnt(dp))
+    if(!argc)
         return throw_type_error(ctx, ei, JS_E_MISSING_ARG, NULL);
 
-    hres = to_number(ctx, get_arg(dp, 0), ei, &n);
+    hres = to_number(ctx, argv, ei, &n);
     if(FAILED(hres))
         return hres;
 
@@ -1391,7 +1391,7 @@ static HRESULT Date_setTime(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISP
 }
 
 /* ECMA-262 3rd Edition    15.9.5.28 */
-static HRESULT Date_setMilliseconds(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Date_setMilliseconds(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     DateInstance *date;
@@ -1403,10 +1403,10 @@ static HRESULT Date_setMilliseconds(script_ctx_t *ctx, vdisp_t *jsthis, WORD fla
     if(!(date = date_this(jsthis)))
         return throw_type_error(ctx, ei, JS_E_DATE_EXPECTED, NULL);
 
-    if(!arg_cnt(dp))
+    if(!argc)
         return throw_type_error(ctx, ei, JS_E_MISSING_ARG, NULL);
 
-    hres = to_number(ctx, get_arg(dp, 0), ei, &n);
+    hres = to_number(ctx, argv, ei, &n);
     if(FAILED(hres))
         return hres;
 
@@ -1422,7 +1422,7 @@ static HRESULT Date_setMilliseconds(script_ctx_t *ctx, vdisp_t *jsthis, WORD fla
 }
 
 /* ECMA-262 3rd Edition    15.9.5.29 */
-static HRESULT Date_setUTCMilliseconds(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Date_setUTCMilliseconds(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     DateInstance *date;
@@ -1434,10 +1434,10 @@ static HRESULT Date_setUTCMilliseconds(script_ctx_t *ctx, vdisp_t *jsthis, WORD
     if(!(date = date_this(jsthis)))
         return throw_type_error(ctx, ei, JS_E_DATE_EXPECTED, NULL);
 
-    if(!arg_cnt(dp))
+    if(!argc)
         return throw_type_error(ctx, ei, JS_E_MISSING_ARG, NULL);
 
-    hres = to_number(ctx, get_arg(dp, 0), ei, &n);
+    hres = to_number(ctx, argv, ei, &n);
     if(FAILED(hres))
         return hres;
 
@@ -1453,7 +1453,7 @@ static HRESULT Date_setUTCMilliseconds(script_ctx_t *ctx, vdisp_t *jsthis, WORD
 }
 
 /* ECMA-262 3rd Edition    15.9.5.30 */
-static HRESULT Date_setSeconds(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Date_setSeconds(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     DateInstance *date;
@@ -1465,17 +1465,17 @@ static HRESULT Date_setSeconds(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, D
     if(!(date = date_this(jsthis)))
         return throw_type_error(ctx, ei, JS_E_DATE_EXPECTED, NULL);
 
-    if(!arg_cnt(dp))
+    if(!argc)
         return throw_type_error(ctx, ei, JS_E_MISSING_ARG, NULL);
 
     t = local_time(date->time, date);
 
-    hres = to_number(ctx, get_arg(dp, 0), ei, &sec);
+    hres = to_number(ctx, argv, ei, &sec);
     if(FAILED(hres))
         return hres;
 
-    if(arg_cnt(dp) > 1) {
-        hres = to_number(ctx, get_arg(dp, 1), ei, &ms);
+    if(argc > 1) {
+        hres = to_number(ctx, argv+1, ei, &ms);
         if(FAILED(hres))
             return hres;
     }else {
@@ -1493,7 +1493,7 @@ static HRESULT Date_setSeconds(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, D
 }
 
 /* ECMA-262 3rd Edition    15.9.5.31 */
-static HRESULT Date_setUTCSeconds(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Date_setUTCSeconds(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     DateInstance *date;
@@ -1505,17 +1505,17 @@ static HRESULT Date_setUTCSeconds(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags
     if(!(date = date_this(jsthis)))
         return throw_type_error(ctx, ei, JS_E_DATE_EXPECTED, NULL);
 
-    if(!arg_cnt(dp))
+    if(!argc)
         return throw_type_error(ctx, ei, JS_E_MISSING_ARG, NULL);
 
     t = date->time;
 
-    hres = to_number(ctx, get_arg(dp, 0), ei, &sec);
+    hres = to_number(ctx, argv, ei, &sec);
     if(FAILED(hres))
         return hres;
 
-    if(arg_cnt(dp) > 1) {
-        hres = to_number(ctx, get_arg(dp, 1), ei, &ms);
+    if(argc > 1) {
+        hres = to_number(ctx, argv+1, ei, &ms);
         if(FAILED(hres))
             return hres;
     }else {
@@ -1533,7 +1533,7 @@ static HRESULT Date_setUTCSeconds(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags
 }
 
 /* ECMA-262 3rd Edition    15.9.5.33 */
-static HRESULT Date_setMinutes(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Date_setMinutes(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     DateInstance *date;
@@ -1545,25 +1545,25 @@ static HRESULT Date_setMinutes(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, D
     if(!(date = date_this(jsthis)))
         return throw_type_error(ctx, ei, JS_E_DATE_EXPECTED, NULL);
 
-    if(!arg_cnt(dp))
+    if(!argc)
         return throw_type_error(ctx, ei, JS_E_MISSING_ARG, NULL);
 
     t = local_time(date->time, date);
 
-    hres = to_number(ctx, get_arg(dp, 0), ei, &min);
+    hres = to_number(ctx, argv, ei, &min);
     if(FAILED(hres))
         return hres;
 
-    if(arg_cnt(dp) > 1) {
-        hres = to_number(ctx, get_arg(dp, 1), ei, &sec);
+    if(argc > 1) {
+        hres = to_number(ctx, argv+1, ei, &sec);
         if(FAILED(hres))
             return hres;
     }else {
         sec = sec_from_time(t);
     }
 
-    if(arg_cnt(dp) > 2) {
-        hres = to_number(ctx, get_arg(dp, 2), ei, &ms);
+    if(argc > 2) {
+        hres = to_number(ctx, argv+2, ei, &ms);
         if(FAILED(hres))
             return hres;
     }else {
@@ -1581,7 +1581,7 @@ static HRESULT Date_setMinutes(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, D
 }
 
 /* ECMA-262 3rd Edition    15.9.5.34 */
-static HRESULT Date_setUTCMinutes(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Date_setUTCMinutes(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     DateInstance *date;
@@ -1593,25 +1593,25 @@ static HRESULT Date_setUTCMinutes(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags
     if(!(date = date_this(jsthis)))
         return throw_type_error(ctx, ei, JS_E_DATE_EXPECTED, NULL);
 
-    if(!arg_cnt(dp))
+    if(!argc)
         return throw_type_error(ctx, ei, JS_E_MISSING_ARG, NULL);
 
     t = date->time;
 
-    hres = to_number(ctx, get_arg(dp, 0), ei, &min);
+    hres = to_number(ctx, argv, ei, &min);
     if(FAILED(hres))
         return hres;
 
-    if(arg_cnt(dp) > 1) {
-        hres = to_number(ctx, get_arg(dp, 1), ei, &sec);
+    if(argc > 1) {
+        hres = to_number(ctx, argv+1, ei, &sec);
         if(FAILED(hres))
             return hres;
     }else {
         sec = sec_from_time(t);
     }
 
-    if(arg_cnt(dp) > 2) {
-        hres = to_number(ctx, get_arg(dp, 2), ei, &ms);
+    if(argc > 2) {
+        hres = to_number(ctx, argv+2, ei, &ms);
         if(FAILED(hres))
             return hres;
     }else {
@@ -1629,7 +1629,7 @@ static HRESULT Date_setUTCMinutes(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags
 }
 
 /* ECMA-262 3rd Edition    15.9.5.35 */
-static HRESULT Date_setHours(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Date_setHours(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     DateInstance *date;
@@ -1641,33 +1641,33 @@ static HRESULT Date_setHours(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DIS
     if(!(date = date_this(jsthis)))
         return throw_type_error(ctx, ei, JS_E_DATE_EXPECTED, NULL);
 
-    if(!arg_cnt(dp))
+    if(!argc)
         return throw_type_error(ctx, ei, JS_E_MISSING_ARG, NULL);
 
     t = local_time(date->time, date);
 
-    hres = to_number(ctx, get_arg(dp, 0), ei, &hour);
+    hres = to_number(ctx, argv, ei, &hour);
     if(FAILED(hres))
         return hres;
 
-    if(arg_cnt(dp) > 1) {
-        hres = to_number(ctx, get_arg(dp, 1), ei, &min);
+    if(argc > 1) {
+        hres = to_number(ctx, argv+1, ei, &min);
         if(FAILED(hres))
             return hres;
     }else {
         min = min_from_time(t);
     }
 
-    if(arg_cnt(dp) > 2) {
-        hres = to_number(ctx, get_arg(dp, 2), ei, &sec);
+    if(argc > 2) {
+        hres = to_number(ctx, argv+2, ei, &sec);
         if(FAILED(hres))
             return hres;
     }else {
         sec = sec_from_time(t);
     }
 
-    if(arg_cnt(dp) > 3) {
-        hres = to_number(ctx, get_arg(dp, 3), ei, &ms);
+    if(argc > 3) {
+        hres = to_number(ctx, argv+3, ei, &ms);
         if(FAILED(hres))
             return hres;
     }else {
@@ -1684,7 +1684,7 @@ static HRESULT Date_setHours(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DIS
 }
 
 /* ECMA-262 3rd Edition    15.9.5.36 */
-static HRESULT Date_setUTCHours(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Date_setUTCHours(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     DateInstance *date;
@@ -1696,33 +1696,33 @@ static HRESULT Date_setUTCHours(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags,
     if(!(date = date_this(jsthis)))
         return throw_type_error(ctx, ei, JS_E_DATE_EXPECTED, NULL);
 
-    if(!arg_cnt(dp))
+    if(!argc)
         return throw_type_error(ctx, ei, JS_E_MISSING_ARG, NULL);
 
     t = date->time;
 
-    hres = to_number(ctx, get_arg(dp, 0), ei, &hour);
+    hres = to_number(ctx, argv, ei, &hour);
     if(FAILED(hres))
         return hres;
 
-    if(arg_cnt(dp) > 1) {
-        hres = to_number(ctx, get_arg(dp, 1), ei, &min);
+    if(argc > 1) {
+        hres = to_number(ctx, argv+1, ei, &min);
         if(FAILED(hres))
             return hres;
     }else {
         min = min_from_time(t);
     }
 
-    if(arg_cnt(dp) > 2) {
-        hres = to_number(ctx, get_arg(dp, 2), ei, &sec);
+    if(argc > 2) {
+        hres = to_number(ctx, argv+2, ei, &sec);
         if(FAILED(hres))
             return hres;
     }else {
         sec = sec_from_time(t);
     }
 
-    if(arg_cnt(dp) > 3) {
-        hres = to_number(ctx, get_arg(dp, 3), ei, &ms);
+    if(argc > 3) {
+        hres = to_number(ctx, argv+3, ei, &ms);
         if(FAILED(hres))
             return hres;
     }else {
@@ -1739,7 +1739,7 @@ static HRESULT Date_setUTCHours(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags,
 }
 
 /* ECMA-262 3rd Edition    15.9.5.36 */
-static HRESULT Date_setDate(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Date_setDate(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     DateInstance *date;
@@ -1751,10 +1751,10 @@ static HRESULT Date_setDate(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISP
     if(!(date = date_this(jsthis)))
         return throw_type_error(ctx, ei, JS_E_DATE_EXPECTED, NULL);
 
-    if(!arg_cnt(dp))
+    if(!argc)
         return throw_type_error(ctx, ei, JS_E_MISSING_ARG, NULL);
 
-    hres = to_number(ctx, get_arg(dp, 0), ei, &n);
+    hres = to_number(ctx, argv, ei, &n);
     if(FAILED(hres))
         return hres;
 
@@ -1769,7 +1769,7 @@ static HRESULT Date_setDate(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISP
 }
 
 /* ECMA-262 3rd Edition    15.9.5.37 */
-static HRESULT Date_setUTCDate(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Date_setUTCDate(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     DateInstance *date;
@@ -1781,10 +1781,10 @@ static HRESULT Date_setUTCDate(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, D
     if(!(date = date_this(jsthis)))
         return throw_type_error(ctx, ei, JS_E_DATE_EXPECTED, NULL);
 
-    if(!arg_cnt(dp))
+    if(!argc)
         return throw_type_error(ctx, ei, JS_E_MISSING_ARG, NULL);
 
-    hres = to_number(ctx, get_arg(dp, 0), ei, &n);
+    hres = to_number(ctx, argv, ei, &n);
     if(FAILED(hres))
         return hres;
 
@@ -1799,7 +1799,7 @@ static HRESULT Date_setUTCDate(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, D
 }
 
 /* ECMA-262 3rd Edition    15.9.5.38 */
-static HRESULT Date_setMonth(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Date_setMonth(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     DateInstance *date;
@@ -1811,17 +1811,17 @@ static HRESULT Date_setMonth(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DIS
     if(!(date = date_this(jsthis)))
         return throw_type_error(ctx, ei, JS_E_DATE_EXPECTED, NULL);
 
-    if(!arg_cnt(dp))
+    if(!argc)
         return throw_type_error(ctx, ei, JS_E_MISSING_ARG, NULL);
 
     t = local_time(date->time, date);
 
-    hres = to_number(ctx, get_arg(dp, 0), ei, &month);
+    hres = to_number(ctx, argv, ei, &month);
     if(FAILED(hres))
         return hres;
 
-    if(arg_cnt(dp) > 1) {
-        hres = to_number(ctx, get_arg(dp, 1), ei, &ddate);
+    if(argc > 1) {
+        hres = to_number(ctx, argv+1, ei, &ddate);
         if(FAILED(hres))
             return hres;
     }else {
@@ -1839,7 +1839,7 @@ static HRESULT Date_setMonth(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DIS
 }
 
 /* ECMA-262 3rd Edition    15.9.5.39 */
-static HRESULT Date_setUTCMonth(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Date_setUTCMonth(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     DateInstance *date;
@@ -1851,17 +1851,17 @@ static HRESULT Date_setUTCMonth(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags,
     if(!(date = date_this(jsthis)))
         return throw_type_error(ctx, ei, JS_E_DATE_EXPECTED, NULL);
 
-    if(!arg_cnt(dp))
+    if(!argc)
         return throw_type_error(ctx, ei, JS_E_MISSING_ARG, NULL);
 
     t = date->time;
 
-    hres = to_number(ctx, get_arg(dp, 0), ei, &month);
+    hres = to_number(ctx, argv, ei, &month);
     if(FAILED(hres))
         return hres;
 
-    if(arg_cnt(dp) > 1) {
-        hres = to_number(ctx, get_arg(dp, 1), ei, &ddate);
+    if(argc > 1) {
+        hres = to_number(ctx, argv+1, ei, &ddate);
         if(FAILED(hres))
             return hres;
     }else {
@@ -1879,7 +1879,7 @@ static HRESULT Date_setUTCMonth(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags,
 }
 
 /* ECMA-262 3rd Edition    15.9.5.40 */
-static HRESULT Date_setFullYear(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Date_setFullYear(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     DateInstance *date;
@@ -1891,25 +1891,25 @@ static HRESULT Date_setFullYear(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags,
     if(!(date = date_this(jsthis)))
         return throw_type_error(ctx, ei, JS_E_DATE_EXPECTED, NULL);
 
-    if(!arg_cnt(dp))
+    if(!argc)
         return throw_type_error(ctx, ei, JS_E_MISSING_ARG, NULL);
 
     t = local_time(date->time, date);
 
-    hres = to_number(ctx, get_arg(dp, 0), ei, &year);
+    hres = to_number(ctx, argv, ei, &year);
     if(FAILED(hres))
         return hres;
 
-    if(arg_cnt(dp) > 1) {
-        hres = to_number(ctx, get_arg(dp, 1), ei, &month);
+    if(argc > 1) {
+        hres = to_number(ctx, argv+1, ei, &month);
         if(FAILED(hres))
             return hres;
     }else {
         month = month_from_time(t);
     }
 
-    if(arg_cnt(dp) > 2) {
-        hres = to_number(ctx, get_arg(dp, 2), ei, &ddate);
+    if(argc > 2) {
+        hres = to_number(ctx, argv+2, ei, &ddate);
         if(FAILED(hres))
             return hres;
     }else {
@@ -1926,7 +1926,7 @@ static HRESULT Date_setFullYear(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags,
 }
 
 /* ECMA-262 3rd Edition    15.9.5.41 */
-static HRESULT Date_setUTCFullYear(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Date_setUTCFullYear(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     DateInstance *date;
@@ -1938,25 +1938,25 @@ static HRESULT Date_setUTCFullYear(script_ctx_t *ctx, vdisp_t *jsthis, WORD flag
     if(!(date = date_this(jsthis)))
         return throw_type_error(ctx, ei, JS_E_DATE_EXPECTED, NULL);
 
-    if(!arg_cnt(dp))
+    if(!argc)
         return throw_type_error(ctx, ei, JS_E_MISSING_ARG, NULL);
 
     t = date->time;
 
-    hres = to_number(ctx, get_arg(dp, 0), ei, &year);
+    hres = to_number(ctx, argv, ei, &year);
     if(FAILED(hres))
         return hres;
 
-    if(arg_cnt(dp) > 1) {
-        hres = to_number(ctx, get_arg(dp, 1), ei, &month);
+    if(argc > 1) {
+        hres = to_number(ctx, argv+1, ei, &month);
         if(FAILED(hres))
             return hres;
     }else {
         month = month_from_time(t);
     }
 
-    if(arg_cnt(dp) > 2) {
-        hres = to_number(ctx, get_arg(dp, 2), ei, &ddate);
+    if(argc > 2) {
+        hres = to_number(ctx, argv+2, ei, &ddate);
         if(FAILED(hres))
             return hres;
     }else {
@@ -1973,7 +1973,7 @@ static HRESULT Date_setUTCFullYear(script_ctx_t *ctx, vdisp_t *jsthis, WORD flag
 }
 
 /* ECMA-262 3rd Edition    B2.4 */
-static HRESULT Date_getYear(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Date_getYear(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     DateInstance *date;
@@ -1999,7 +1999,7 @@ static HRESULT Date_getYear(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISP
 }
 
 /* ECMA-262 3rd Edition    B2.5 */
-static HRESULT Date_setYear(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Date_setYear(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     DateInstance *date;
@@ -2011,12 +2011,12 @@ static HRESULT Date_setYear(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISP
     if(!(date = date_this(jsthis)))
         return throw_type_error(ctx, ei, JS_E_DATE_EXPECTED, NULL);
 
-    if(!arg_cnt(dp))
+    if(!argc)
         return throw_type_error(ctx, ei, JS_E_MISSING_ARG, NULL);
 
     t = local_time(date->time, date);
 
-    hres = to_number(ctx, get_arg(dp, 0), ei, &year);
+    hres = to_number(ctx, argv, ei, &year);
     if(FAILED(hres))
         return hres;
 
@@ -2038,7 +2038,7 @@ static HRESULT Date_setYear(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISP
     return S_OK;
 }
 
-static HRESULT Date_value(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Date_value(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     TRACE("\n");
@@ -2403,7 +2403,7 @@ static inline HRESULT date_parse(BSTR input, double *ret) {
     return S_OK;
 }
 
-static HRESULT DateConstr_parse(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT DateConstr_parse(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     BSTR parse_str;
@@ -2412,13 +2412,13 @@ static HRESULT DateConstr_parse(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags,
 
     TRACE("\n");
 
-    if(!arg_cnt(dp)) {
+    if(!argc) {
         if(retv)
             num_set_val(retv, NAN);
         return S_OK;
     }
 
-    hres = to_string(ctx, get_arg(dp,0), ei, &parse_str);
+    hres = to_string(ctx, argv, ei, &parse_str);
     if(FAILED(hres))
         return hres;
 
@@ -2431,16 +2431,15 @@ static HRESULT DateConstr_parse(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags,
     return S_OK;
 }
 
-static HRESULT date_utc(script_ctx_t *ctx, DISPPARAMS *dp, double *ret, jsexcept_t *ei)
+static HRESULT date_utc(script_ctx_t *ctx, unsigned argc, VARIANT *argv, double *ret, jsexcept_t *ei)
 {
     double year, month, vdate, hours, minutes, seconds, ms;
-    int arg_no = arg_cnt(dp);
     HRESULT hres;
 
     TRACE("\n");
 
-    if(arg_no>0) {
-        hres = to_number(ctx, get_arg(dp, 0), ei, &year);
+    if(argc) {
+        hres = to_number(ctx, argv, ei, &year);
         if(FAILED(hres))
             return hres;
         if(0 <= year && year <= 99)
@@ -2449,48 +2448,48 @@ static HRESULT date_utc(script_ctx_t *ctx, DISPPARAMS *dp, double *ret, jsexcept
         year = 1900;
     }
 
-    if(arg_no>1) {
-        hres = to_number(ctx, get_arg(dp, 1), ei, &month);
+    if(argc>1) {
+        hres = to_number(ctx, argv+1, ei, &month);
         if(FAILED(hres))
             return hres;
     }else {
         month = 0;
     }
 
-    if(arg_no>2) {
-        hres = to_number(ctx, get_arg(dp, 2), ei, &vdate);
+    if(argc>2) {
+        hres = to_number(ctx, argv+2, ei, &vdate);
         if(FAILED(hres))
             return hres;
     }else {
         vdate = 1;
     }
 
-    if(arg_no>3) {
-        hres = to_number(ctx, get_arg(dp, 3), ei, &hours);
+    if(argc>3) {
+        hres = to_number(ctx, argv+3, ei, &hours);
         if(FAILED(hres))
             return hres;
     }else {
         hours = 0;
     }
 
-    if(arg_no>4) {
-        hres = to_number(ctx, get_arg(dp, 4), ei, &minutes);
+    if(argc>4) {
+        hres = to_number(ctx, argv+4, ei, &minutes);
         if(FAILED(hres))
             return hres;
     }else {
         minutes = 0;
     }
 
-    if(arg_no>5) {
-        hres = to_number(ctx, get_arg(dp, 5), ei, &seconds);
+    if(argc>5) {
+        hres = to_number(ctx, argv+5, ei, &seconds);
         if(FAILED(hres))
             return hres;
     }else {
         seconds = 0;
     }
 
-    if(arg_no>6) {
-        hres = to_number(ctx, get_arg(dp, 6), ei, &ms);
+    if(argc>6) {
+        hres = to_number(ctx, argv+6, ei, &ms);
         if(FAILED(hres))
             return hres;
     } else {
@@ -2502,7 +2501,7 @@ static HRESULT date_utc(script_ctx_t *ctx, DISPPARAMS *dp, double *ret, jsexcept
     return S_OK;
 }
 
-static HRESULT DateConstr_UTC(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT DateConstr_UTC(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     double n;
@@ -2510,13 +2509,13 @@ static HRESULT DateConstr_UTC(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DI
 
     TRACE("\n");
 
-    hres = date_utc(ctx, dp, &n, ei);
+    hres = date_utc(ctx, argc, argv, &n, ei);
     if(SUCCEEDED(hres) && retv)
         num_set_val(retv, n);
     return hres;
 }
 
-static HRESULT DateConstr_value(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT DateConstr_value(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     jsdisp_t *date;
@@ -2526,7 +2525,7 @@ static HRESULT DateConstr_value(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags,
 
     switch(flags) {
     case DISPATCH_CONSTRUCT:
-        switch(arg_cnt(dp)) {
+        switch(argc) {
         /* ECMA-262 3rd Edition    15.9.3.3 */
         case 0: {
             FILETIME time;
@@ -2547,7 +2546,7 @@ static HRESULT DateConstr_value(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags,
             VARIANT prim;
             double n;
 
-            hres = to_primitive(ctx, get_arg(dp,0), ei, &prim, NO_HINT);
+            hres = to_primitive(ctx, argv, ei, &prim, NO_HINT);
             if(FAILED(hres))
                 return hres;
 
@@ -2571,7 +2570,7 @@ static HRESULT DateConstr_value(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags,
             double ret_date;
             DateInstance *di;
 
-            hres = date_utc(ctx, dp, &ret_date, ei);
+            hres = date_utc(ctx, argc, argv, &ret_date, ei);
             if(FAILED(hres))
                 return hres;
 
diff --git a/dlls/jscript/dispex.c b/dlls/jscript/dispex.c
index c52ac7d431e..5bec3d4b03d 100644
--- a/dlls/jscript/dispex.c
+++ b/dlls/jscript/dispex.c
@@ -291,48 +291,6 @@ static HRESULT ensure_prop_name(jsdisp_t *This, const WCHAR *name, BOOL search_p
     return hres;
 }
 
-static HRESULT set_this(DISPPARAMS *dp, const DISPPARAMS *olddp, IDispatch *jsthis)
-{
-    VARIANTARG *oldargs;
-    int i;
-
-    static DISPID this_id = DISPID_THIS;
-
-    *dp = *olddp;
-
-    for(i = 0; i < dp->cNamedArgs; i++) {
-        if(dp->rgdispidNamedArgs[i] == DISPID_THIS)
-            return S_OK;
-    }
-
-    oldargs = dp->rgvarg;
-    dp->rgvarg = heap_alloc((dp->cArgs+1) * sizeof(VARIANTARG));
-    if(!dp->rgvarg)
-        return E_OUTOFMEMORY;
-    memcpy(dp->rgvarg+1, oldargs, dp->cArgs*sizeof(VARIANTARG));
-    V_VT(dp->rgvarg) = VT_DISPATCH;
-    V_DISPATCH(dp->rgvarg) = jsthis;
-    dp->cArgs++;
-
-    if(dp->cNamedArgs) {
-        DISPID *old = dp->rgdispidNamedArgs;
-        dp->rgdispidNamedArgs = heap_alloc((dp->cNamedArgs+1)*sizeof(DISPID));
-        if(!dp->rgdispidNamedArgs) {
-            heap_free(dp->rgvarg);
-            return E_OUTOFMEMORY;
-        }
-
-        memcpy(dp->rgdispidNamedArgs+1, old, dp->cNamedArgs*sizeof(DISPID));
-        dp->rgdispidNamedArgs[0] = DISPID_THIS;
-        dp->cNamedArgs++;
-    }else {
-        dp->rgdispidNamedArgs = &this_id;
-        dp->cNamedArgs = 1;
-    }
-
-    return S_OK;
-}
-
 static IDispatch *get_this(DISPPARAMS *dp)
 {
     DWORD i;
@@ -351,60 +309,46 @@ static IDispatch *get_this(DISPPARAMS *dp)
     return NULL;
 }
 
-static HRESULT convert_params(const DISPPARAMS *dp, VARIANT *buf, DISPPARAMS *ret)
+static HRESULT convert_params(const DISPPARAMS *dp, VARIANT *buf, unsigned *argc, VARIANT **ret)
 {
-    BOOL need_conversion = FALSE;
     const VARIANT *s;
-    VARIANT *d;
+    VARIANT *argv;
+    unsigned cnt;
     unsigned i;
 
-    ret->cArgs = dp->cArgs - dp->cNamedArgs;
-    ret->cNamedArgs = 0;
+    cnt = dp->cArgs - dp->cNamedArgs;
 
-    for(i = 0; i < ret->cArgs && !need_conversion; i++) {
-        switch(V_VT(get_arg(dp, i))) {
-        case VT_I2:
-        case VT_INT:
-            need_conversion = TRUE;
-            break;
-        }
-    }
-
-    if(!need_conversion) {
-        ret->rgvarg = dp->rgvarg + dp->cNamedArgs;
-        return S_OK;
-    }
-
-    if(ret->cArgs > 6) {
-        ret->rgvarg = heap_alloc(ret->cArgs * sizeof(VARIANT));
-        if(!ret->rgvarg)
+    if(cnt > 6) {
+        argv = heap_alloc(cnt * sizeof(VARIANT));
+        if(!argv)
             return E_OUTOFMEMORY;
     }else {
-        ret->rgvarg = buf;
+        argv = buf;
     }
 
-    for(i = 0; i < ret->cArgs; i++) {
+    for(i = 0; i < cnt; i++) {
         s = get_arg(dp, i);
-        d = get_arg(ret, i);
         switch(V_VT(s)) {
         case VT_I2:
-            V_VT(d) = VT_I4;
-            V_I4(d) = V_I2(s);
+            V_VT(argv+i) = VT_I4;
+            V_I4(argv+i) = V_I2(s);
             break;
         case VT_INT:
-            V_VT(d) = VT_I4;
-            V_I4(d) = V_INT(s);
+            V_VT(argv+i) = VT_I4;
+            V_I4(argv+i) = V_INT(s);
             break;
         default:
-            *d = *s;
+            argv[i] = *s;
         }
     }
 
+    *argc = cnt;
+    *ret = argv;
     return S_OK;
 }
 
 static HRESULT invoke_prop_func(jsdisp_t *This, IDispatch *jsthis, dispex_prop_t *prop, WORD flags,
-        DISPPARAMS *dp, VARIANT *retv, jsexcept_t *ei, IServiceProvider *caller)
+        unsigned argc, VARIANT *argv, VARIANT *retv, jsexcept_t *ei, IServiceProvider *caller)
 {
     HRESULT hres;
 
@@ -422,16 +366,17 @@ static HRESULT invoke_prop_func(jsdisp_t *This, IDispatch *jsthis, dispex_prop_t
                 set_disp(&vthis, jsthis);
             else
                 set_jsdisp(&vthis, This);
-            hres = prop->u.p->invoke(This->ctx, &vthis, flags, dp, retv, ei);
+            hres = prop->u.p->invoke(This->ctx, &vthis, flags, argc, argv, retv, ei);
             vdisp_release(&vthis);
         }else {
             /* Function object calls are special case */
-            hres = Function_invoke(This, jsthis, flags, dp, retv, ei);
+            hres = Function_invoke(This, jsthis, flags, argc, argv, retv, ei);
         }
         return hres;
     }
     case PROP_PROTREF:
-        return invoke_prop_func(This->prototype, jsthis, This->prototype->props+prop->u.ref, flags, dp, retv, ei, caller);
+        return invoke_prop_func(This->prototype, jsthis, This->prototype->props+prop->u.ref,
+                flags, argc, argv, retv, ei, caller);
     case PROP_VARIANT: {
         if(V_VT(&prop->u.var) != VT_DISPATCH) {
             FIXME("invoke vt %d\n", V_VT(&prop->u.var));
@@ -440,7 +385,7 @@ static HRESULT invoke_prop_func(jsdisp_t *This, IDispatch *jsthis, dispex_prop_t
 
         TRACE("call %s %p\n", debugstr_w(prop->name), V_DISPATCH(&prop->u.var));
 
-        return disp_call_value(This->ctx, V_DISPATCH(&prop->u.var), jsthis, flags, dp, retv, ei);
+        return disp_call_value(This->ctx, V_DISPATCH(&prop->u.var), jsthis, flags, argc, argv, retv, ei);
     }
     default:
         ERR("type %d\n", prop->type);
@@ -470,7 +415,7 @@ static HRESULT prop_get(jsdisp_t *This, dispex_prop_t *prop, DISPPARAMS *dp,
             vdisp_t vthis;
 
             set_jsdisp(&vthis, This);
-            hres = prop->u.p->invoke(This->ctx, &vthis, DISPATCH_PROPERTYGET, dp, retv, ei);
+            hres = prop->u.p->invoke(This->ctx, &vthis, DISPATCH_PROPERTYGET, 0, NULL, retv, ei);
             vdisp_release(&vthis);
         }
         break;
@@ -505,11 +450,10 @@ static HRESULT prop_put(jsdisp_t *This, dispex_prop_t *prop, VARIANT *val,
     switch(prop->type) {
     case PROP_BUILTIN:
         if(!(prop->flags & PROPF_METHOD)) {
-            DISPPARAMS dp = {val, NULL, 1, 0};
             vdisp_t vthis;
 
             set_jsdisp(&vthis, This);
-            hres = prop->u.p->invoke(This->ctx, &vthis, DISPATCH_PROPERTYPUT, &dp, NULL, ei);
+            hres = prop->u.p->invoke(This->ctx, &vthis, DISPATCH_PROPERTYPUT, 1, val, NULL, ei);
             vdisp_release(&vthis);
             return hres;
         }
@@ -733,16 +677,17 @@ static HRESULT WINAPI DispatchEx_InvokeEx(IDispatchEx *iface, DISPID id, LCID lc
         /* fall through */
     case DISPATCH_METHOD:
     case DISPATCH_CONSTRUCT: {
-        DISPPARAMS params;
+        VARIANT *argv;
+        unsigned argc;
         VARIANT buf[6];
 
-        hres = convert_params(pdp, buf, &params);
+        hres = convert_params(pdp, buf, &argc, &argv);
         if(FAILED(hres))
             return hres;
 
-        hres = invoke_prop_func(This, get_this(pdp), prop, wFlags, &params, pvarRes, &jsexcept, pspCaller);
-        if(params.rgvarg != buf && params.rgvarg != pdp->rgvarg)
-            heap_free(params.rgvarg);
+        hres = invoke_prop_func(This, get_this(pdp), prop, wFlags, argc, argv, pvarRes, &jsexcept, pspCaller);
+        if(argv != buf)
+            heap_free(argv);
         break;
     }
     case DISPATCH_PROPERTYGET:
@@ -1066,25 +1011,24 @@ HRESULT jsdisp_get_id(jsdisp_t *jsdisp, const WCHAR *name, DWORD flags, DISPID *
     return DISP_E_UNKNOWNNAME;
 }
 
-HRESULT jsdisp_call_value(jsdisp_t *jsfunc, IDispatch *jsthis, WORD flags, DISPPARAMS *dp, VARIANT *retv, jsexcept_t *ei)
+HRESULT jsdisp_call_value(jsdisp_t *jsfunc, IDispatch *jsthis, WORD flags, unsigned argc, VARIANT *argv, VARIANT *retv,
+        jsexcept_t *ei)
 {
     HRESULT hres;
 
-    TRACE("args %p\n", dp->rgvarg);
-
     if(is_class(jsfunc, JSCLASS_FUNCTION)) {
-        hres = Function_invoke(jsfunc, jsthis, flags, dp, retv, ei);
+        hres = Function_invoke(jsfunc, jsthis, flags, argc, argv, retv, ei);
     }else {
         vdisp_t vdisp;
 
         set_disp(&vdisp, jsthis);
-        hres = jsfunc->builtin_info->value_prop.invoke(jsfunc->ctx, &vdisp, flags, dp, retv, ei);
+        hres = jsfunc->builtin_info->value_prop.invoke(jsfunc->ctx, &vdisp, flags, argc, argv, retv, ei);
         vdisp_release(&vdisp);
     }
     return hres;
 }
 
-HRESULT jsdisp_call(jsdisp_t *disp, DISPID id, WORD flags, DISPPARAMS *dp, VARIANT *retv, jsexcept_t *ei)
+HRESULT jsdisp_call(jsdisp_t *disp, DISPID id, WORD flags, unsigned argc, VARIANT *argv, VARIANT *retv, jsexcept_t *ei)
 {
     dispex_prop_t *prop;
 
@@ -1096,10 +1040,10 @@ HRESULT jsdisp_call(jsdisp_t *disp, DISPID id, WORD flags, DISPPARAMS *dp, VARIA
     if(!prop)
         return DISP_E_MEMBERNOTFOUND;
 
-    return invoke_prop_func(disp, to_disp(disp), prop, flags, dp, retv, ei, NULL);
+    return invoke_prop_func(disp, to_disp(disp), prop, flags, argc, argv, retv, ei, NULL);
 }
 
-HRESULT jsdisp_call_name(jsdisp_t *disp, const WCHAR *name, WORD flags, DISPPARAMS *dp, VARIANT *retv,
+HRESULT jsdisp_call_name(jsdisp_t *disp, const WCHAR *name, WORD flags, unsigned argc, VARIANT *argv, VARIANT *retv,
         jsexcept_t *ei)
 {
     dispex_prop_t *prop;
@@ -1113,13 +1057,17 @@ HRESULT jsdisp_call_name(jsdisp_t *disp, const WCHAR *name, WORD flags, DISPPARA
     if(retv)
         V_VT(retv) = VT_EMPTY;
 
-    return invoke_prop_func(disp, to_disp(disp), prop, flags, dp, retv, ei, NULL);
+    return invoke_prop_func(disp, to_disp(disp), prop, flags, argc, argv, retv, ei, NULL);
 }
 
-HRESULT disp_call(script_ctx_t *ctx, IDispatch *disp, DISPID id, WORD flags, DISPPARAMS *dp, VARIANT *retv, jsexcept_t *ei)
+HRESULT disp_call(script_ctx_t *ctx, IDispatch *disp, DISPID id, WORD flags, unsigned argc, VARIANT *argv,
+        VARIANT *retv, jsexcept_t *ei)
 {
-    jsdisp_t *jsdisp;
     IDispatchEx *dispex;
+    jsdisp_t *jsdisp;
+    VARIANT buf[6];
+    DISPPARAMS dp;
+    unsigned i;
     HRESULT hres;
 
     jsdisp = iface_to_jsdisp((IUnknown*)disp);
@@ -1129,20 +1077,44 @@ HRESULT disp_call(script_ctx_t *ctx, IDispatch *disp, DISPID id, WORD flags, DIS
             return E_FAIL;
         }
 
-        hres = jsdisp_call(jsdisp, id, flags, dp, retv, ei);
+        hres = jsdisp_call(jsdisp, id, flags, argc, argv, retv, ei);
         jsdisp_release(jsdisp);
         return hres;
     }
 
     memset(ei, 0, sizeof(*ei));
-    if(retv && arg_cnt(dp))
+    if(retv && argc)
         flags |= DISPATCH_PROPERTYGET;
 
+    dp.cArgs = argc;
+
+    if(flags & DISPATCH_PROPERTYPUT) {
+        static DISPID propput_dispid = DISPID_PROPERTYPUT;
+
+        dp.cNamedArgs = 1;
+        dp.rgdispidNamedArgs = &propput_dispid;
+    }else {
+        dp.cNamedArgs = 0;
+        dp.rgdispidNamedArgs = NULL;
+    }
+
+    if(argc > 6) {
+        dp.rgvarg = heap_alloc(argc*sizeof(VARIANT));
+        if(!dp.rgvarg)
+            return E_OUTOFMEMORY;
+    }else {
+        dp.rgvarg = buf;
+    }
+
+    for(i=0; i<argc; i++)
+        dp.rgvarg[argc-i-1] = argv[i];
+
     if(retv)
         V_VT(retv) = VT_EMPTY;
+
     hres = IDispatch_QueryInterface(disp, &IID_IDispatchEx, (void**)&dispex);
     if(SUCCEEDED(hres)) {
-        hres = IDispatchEx_InvokeEx(dispex, id, ctx->lcid, flags, dp, retv, &ei->ei, &ctx->jscaller->IServiceProvider_iface);
+        hres = IDispatchEx_InvokeEx(dispex, id, ctx->lcid, flags, &dp, retv, &ei->ei, &ctx->jscaller->IServiceProvider_iface);
         IDispatchEx_Release(dispex);
     }else {
         UINT err = 0;
@@ -1153,9 +1125,11 @@ HRESULT disp_call(script_ctx_t *ctx, IDispatch *disp, DISPID id, WORD flags, DIS
         }
 
         TRACE("using IDispatch\n");
-        hres = IDispatch_Invoke(disp, id, &IID_NULL, ctx->lcid, flags, dp, retv, &ei->ei, &err);
+        hres = IDispatch_Invoke(disp, id, &IID_NULL, ctx->lcid, flags, &dp, retv, &ei->ei, &err);
     }
 
+    if(dp.rgvarg != buf)
+        heap_free(dp.rgvarg);
     if(FAILED(hres))
         return hres;
 
@@ -1164,12 +1138,14 @@ HRESULT disp_call(script_ctx_t *ctx, IDispatch *disp, DISPID id, WORD flags, DIS
     return S_OK;
 }
 
-HRESULT disp_call_value(script_ctx_t *ctx, IDispatch *disp, IDispatch *jsthis, WORD flags, DISPPARAMS *dp,
+HRESULT disp_call_value(script_ctx_t *ctx, IDispatch *disp, IDispatch *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
-    DISPPARAMS params;
     jsdisp_t *jsdisp;
     IDispatchEx *dispex;
+    VARIANT buf[6];
+    DISPPARAMS dp;
+    unsigned i;
     HRESULT hres;
 
     jsdisp = iface_to_jsdisp((IUnknown*)disp);
@@ -1179,28 +1155,48 @@ HRESULT disp_call_value(script_ctx_t *ctx, IDispatch *disp, IDispatch *jsthis, W
             return E_FAIL;
         }
 
-        hres = jsdisp_call_value(jsdisp, jsthis, flags, dp, retv, ei);
+        hres = jsdisp_call_value(jsdisp, jsthis, flags, argc, argv, retv, ei);
         jsdisp_release(jsdisp);
         return hres;
     }
 
     memset(ei, 0, sizeof(*ei));
-    if(retv && arg_cnt(dp))
+    if(retv && argc)
         flags |= DISPATCH_PROPERTYGET;
 
+
     if(jsthis) {
-        hres = set_this(&params, dp, jsthis);
-        if(FAILED(hres))
-            return hres;
+        static DISPID this_id = DISPID_THIS;
+
+        dp.cArgs = argc+1;
+        dp.cNamedArgs = 1;
+        dp.rgdispidNamedArgs = &this_id;
     }else {
-        params = *dp;
+        dp.cArgs = argc;
+        dp.cNamedArgs = 0;
+        dp.rgdispidNamedArgs = NULL;
+    }
+
+    if(dp.cArgs > sizeof(buf)/sizeof(*buf)) {
+        dp.rgvarg = heap_alloc(dp.cArgs*sizeof(VARIANT));
+        if(!dp.rgvarg)
+            return E_OUTOFMEMORY;
+    }else {
+        dp.rgvarg = buf;
+    }
+
+    for(i=0; i<argc; i++)
+        dp.rgvarg[argc-i-1] = argv[i];
+    if(jsthis) {
+        V_VT(dp.rgvarg) = VT_DISPATCH;
+        V_DISPATCH(dp.rgvarg) = jsthis;
     }
 
     if(retv)
         V_VT(retv) = VT_EMPTY;
     hres = IDispatch_QueryInterface(disp, &IID_IDispatchEx, (void**)&dispex);
     if(SUCCEEDED(hres)) {
-        hres = IDispatchEx_InvokeEx(dispex, DISPID_VALUE, ctx->lcid, flags, &params, retv, &ei->ei,
+        hres = IDispatchEx_InvokeEx(dispex, DISPID_VALUE, ctx->lcid, flags, &dp, retv, &ei->ei,
                 &ctx->jscaller->IServiceProvider_iface);
         IDispatchEx_Release(dispex);
     }else {
@@ -1212,15 +1208,11 @@ HRESULT disp_call_value(script_ctx_t *ctx, IDispatch *disp, IDispatch *jsthis, W
         }
 
         TRACE("using IDispatch\n");
-        hres = IDispatch_Invoke(disp, DISPID_VALUE, &IID_NULL, ctx->lcid, flags, &params, retv, &ei->ei, &err);
-    }
-
-    if(params.rgvarg != dp->rgvarg) {
-        heap_free(params.rgvarg);
-        if(params.cNamedArgs > 1)
-            heap_free(params.rgdispidNamedArgs);
+        hres = IDispatch_Invoke(disp, DISPID_VALUE, &IID_NULL, ctx->lcid, flags, &dp, retv, &ei->ei, &err);
     }
 
+    if(dp.rgvarg != buf)
+        heap_free(dp.rgvarg);
     if(FAILED(hres))
         return hres;
 
diff --git a/dlls/jscript/engine.c b/dlls/jscript/engine.c
index 3b20e6aede4..e6c26462b45 100644
--- a/dlls/jscript/engine.c
+++ b/dlls/jscript/engine.c
@@ -133,6 +133,14 @@ static inline VARIANT *stack_topn(exec_ctx_t *ctx, unsigned n)
     return ctx->stack + ctx->top-1-n;
 }
 
+static inline VARIANT *stack_args(exec_ctx_t *ctx, unsigned n)
+{
+    if(!n)
+        return NULL;
+    assert(ctx->top > n-1);
+    return ctx->stack + ctx->top-n;
+}
+
 static inline VARIANT *stack_pop(exec_ctx_t *ctx)
 {
     assert(ctx->top);
@@ -972,32 +980,11 @@ static HRESULT interp_refval(exec_ctx_t *ctx)
     return stack_push(ctx, &v);
 }
 
-static void jsstack_to_dp(exec_ctx_t *ctx, unsigned arg_cnt, DISPPARAMS *dp)
-{
-    VARIANT tmp;
-    unsigned i;
-
-    dp->cArgs = arg_cnt;
-    dp->rgdispidNamedArgs = NULL;
-    dp->cNamedArgs = 0;
-
-    assert(ctx->top >= arg_cnt);
-
-    for(i=1; i*2 <= arg_cnt; i++) {
-        tmp = ctx->stack[ctx->top-i];
-        ctx->stack[ctx->top-i] = ctx->stack[ctx->top-arg_cnt+i-1];
-        ctx->stack[ctx->top-arg_cnt+i-1] = tmp;
-    }
-
-    dp->rgvarg = ctx->stack + ctx->top-arg_cnt;
-}
-
 /* ECMA-262 3rd Edition    11.2.2 */
 static HRESULT interp_new(exec_ctx_t *ctx)
 {
     const unsigned arg = get_op_uint(ctx, 0);
     VARIANT *constr, v;
-    DISPPARAMS dp;
     HRESULT hres;
 
     TRACE("%d\n", arg);
@@ -1013,8 +1000,7 @@ static HRESULT interp_new(exec_ctx_t *ctx)
     else if(!V_DISPATCH(constr))
         return throw_type_error(ctx->script, ctx->ei, JS_E_INVALID_PROPERTY, NULL);
 
-    jsstack_to_dp(ctx, arg, &dp);
-    hres = disp_call_value(ctx->script, V_DISPATCH(constr), NULL, DISPATCH_CONSTRUCT, &dp, &v, ctx->ei);
+    hres = disp_call_value(ctx->script, V_DISPATCH(constr), NULL, DISPATCH_CONSTRUCT, arg, stack_args(ctx, arg), &v, ctx->ei);
     if(FAILED(hres))
         return hres;
 
@@ -1028,7 +1014,6 @@ static HRESULT interp_call(exec_ctx_t *ctx)
     const unsigned argn = get_op_uint(ctx, 0);
     const int do_ret = get_op_int(ctx, 1);
     VARIANT v, *objv;
-    DISPPARAMS dp;
     HRESULT hres;
 
     TRACE("%d %d\n", argn, do_ret);
@@ -1037,8 +1022,7 @@ static HRESULT interp_call(exec_ctx_t *ctx)
     if(V_VT(objv) != VT_DISPATCH)
         return throw_type_error(ctx->script, ctx->ei, JS_E_INVALID_PROPERTY, NULL);
 
-    jsstack_to_dp(ctx, argn, &dp);
-    hres = disp_call_value(ctx->script, V_DISPATCH(objv), NULL, DISPATCH_METHOD, &dp,
+    hres = disp_call_value(ctx->script, V_DISPATCH(objv), NULL, DISPATCH_METHOD, argn, stack_args(ctx, argn),
             do_ret ? &v : NULL, ctx->ei);
     if(FAILED(hres))
         return hres;
@@ -1054,7 +1038,6 @@ static HRESULT interp_call_member(exec_ctx_t *ctx)
     const unsigned argn = get_op_uint(ctx, 0);
     const int do_ret = get_op_int(ctx, 1);
     IDispatch *obj;
-    DISPPARAMS dp;
     VARIANT v;
     DISPID id;
     HRESULT hres;
@@ -1065,8 +1048,7 @@ static HRESULT interp_call_member(exec_ctx_t *ctx)
     if(!obj)
         return throw_type_error(ctx->script, ctx->ei, id, NULL);
 
-    jsstack_to_dp(ctx, argn, &dp);
-    hres = disp_call(ctx->script, obj, id, DISPATCH_METHOD, &dp, do_ret ? &v : NULL, ctx->ei);
+    hres = disp_call(ctx->script, obj, id, DISPATCH_METHOD, argn, stack_args(ctx, argn), do_ret ? &v : NULL, ctx->ei);
     if(FAILED(hres))
         return hres;
 
@@ -2398,9 +2380,7 @@ static HRESULT interp_assign(exec_ctx_t *ctx)
 static HRESULT interp_assign_call(exec_ctx_t *ctx)
 {
     const unsigned arg = get_op_uint(ctx, 0);
-    DISPID propput_dispid = DISPID_PROPERTYPUT;
     IDispatch *disp;
-    DISPPARAMS dp;
     VARIANT *v;
     DISPID id;
     HRESULT hres;
@@ -2411,10 +2391,7 @@ static HRESULT interp_assign_call(exec_ctx_t *ctx)
     if(!disp)
         return throw_reference_error(ctx->script, ctx->ei, JS_E_ILLEGAL_ASSIGN, NULL);
 
-    jsstack_to_dp(ctx, arg+1, &dp);
-    dp.cNamedArgs = 1;
-    dp.rgdispidNamedArgs = &propput_dispid;
-    hres = disp_call(ctx->script, disp, id, DISPATCH_PROPERTYPUT, &dp, NULL, ctx->ei);
+    hres = disp_call(ctx->script, disp, id, DISPATCH_PROPERTYPUT, arg+1, stack_args(ctx,arg+1), NULL, ctx->ei);
     if(FAILED(hres))
         return hres;
 
diff --git a/dlls/jscript/error.c b/dlls/jscript/error.c
index 31117149b40..aa948c685b7 100644
--- a/dlls/jscript/error.c
+++ b/dlls/jscript/error.c
@@ -35,7 +35,7 @@ static const WCHAR toStringW[] = {'t','o','S','t','r','i','n','g',0};
 
 /* ECMA-262 3rd Edition    15.11.4.4 */
 static HRESULT Error_toString(script_ctx_t *ctx, vdisp_t *vthis, WORD flags,
-        DISPPARAMS *dp, VARIANT *retv, jsexcept_t *ei)
+        unsigned argc, VARIANT *argv, VARIANT *retv, jsexcept_t *ei)
 {
     jsdisp_t *jsthis;
     BSTR name = NULL, msg = NULL, ret = NULL;
@@ -127,7 +127,7 @@ static HRESULT Error_toString(script_ctx_t *ctx, vdisp_t *vthis, WORD flags,
 }
 
 static HRESULT Error_value(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags,
-        DISPPARAMS *dp, VARIANT *retv, jsexcept_t *ei)
+        unsigned argc, VARIANT *argv, VARIANT *retv, jsexcept_t *ei)
 {
     TRACE("\n");
 
@@ -226,28 +226,28 @@ static HRESULT create_error(script_ctx_t *ctx, jsdisp_t *constr,
     return S_OK;
 }
 
-static HRESULT error_constr(script_ctx_t *ctx, WORD flags, DISPPARAMS *dp,
+static HRESULT error_constr(script_ctx_t *ctx, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei, jsdisp_t *constr) {
     jsdisp_t *err;
     UINT num = 0;
     BSTR msg = NULL;
     HRESULT hres;
 
-    if(arg_cnt(dp)) {
+    if(argc) {
         double n;
 
-        hres = to_number(ctx, get_arg(dp, 0), ei, &n);
+        hres = to_number(ctx, argv, ei, &n);
         if(FAILED(hres)) /* FIXME: really? */
             n = NAN;
         if(isnan(n))
-            hres = to_string(ctx, get_arg(dp, 0), ei, &msg);
+            hres = to_string(ctx, argv, ei, &msg);
         if(FAILED(hres))
             return hres;
         num = n;
     }
 
-    if(arg_cnt(dp)>1 && !msg) {
-        hres = to_string(ctx, get_arg(dp, 1), ei, &msg);
+    if(argc>1 && !msg) {
+        hres = to_string(ctx, argv+1, ei, &msg);
         if(FAILED(hres))
             return hres;
     }
@@ -275,59 +275,59 @@ static HRESULT error_constr(script_ctx_t *ctx, WORD flags, DISPPARAMS *dp,
 }
 
 static HRESULT ErrorConstr_value(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags,
-        DISPPARAMS *dp, VARIANT *retv, jsexcept_t *ei)
+        unsigned argc, VARIANT *argv, VARIANT *retv, jsexcept_t *ei)
 {
     TRACE("\n");
-    return error_constr(ctx, flags, dp, retv, ei, ctx->error_constr);
+    return error_constr(ctx, flags, argc, argv, retv, ei, ctx->error_constr);
 }
 
 static HRESULT EvalErrorConstr_value(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags,
-        DISPPARAMS *dp, VARIANT *retv, jsexcept_t *ei)
+        unsigned argc, VARIANT *argv, VARIANT *retv, jsexcept_t *ei)
 {
     TRACE("\n");
-    return error_constr(ctx, flags, dp, retv, ei, ctx->eval_error_constr);
+    return error_constr(ctx, flags, argc, argv, retv, ei, ctx->eval_error_constr);
 }
 
 static HRESULT RangeErrorConstr_value(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags,
-        DISPPARAMS *dp, VARIANT *retv, jsexcept_t *ei)
+        unsigned argc, VARIANT *argv, VARIANT *retv, jsexcept_t *ei)
 {
     TRACE("\n");
-    return error_constr(ctx, flags, dp, retv, ei, ctx->range_error_constr);
+    return error_constr(ctx, flags, argc, argv, retv, ei, ctx->range_error_constr);
 }
 
 static HRESULT ReferenceErrorConstr_value(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags,
-        DISPPARAMS *dp, VARIANT *retv, jsexcept_t *ei)
+        unsigned argc, VARIANT *argv, VARIANT *retv, jsexcept_t *ei)
 {
     TRACE("\n");
-    return error_constr(ctx, flags, dp, retv, ei, ctx->reference_error_constr);
+    return error_constr(ctx, flags, argc, argv, retv, ei, ctx->reference_error_constr);
 }
 
 static HRESULT RegExpErrorConstr_value(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags,
-        DISPPARAMS *dp, VARIANT *retv, jsexcept_t *ei)
+        unsigned argc, VARIANT *argv, VARIANT *retv, jsexcept_t *ei)
 {
     TRACE("\n");
-    return error_constr(ctx, flags, dp, retv, ei, ctx->regexp_error_constr);
+    return error_constr(ctx, flags, argc, argv, retv, ei, ctx->regexp_error_constr);
 }
 
 static HRESULT SyntaxErrorConstr_value(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags,
-        DISPPARAMS *dp, VARIANT *retv, jsexcept_t *ei)
+        unsigned argc, VARIANT *argv, VARIANT *retv, jsexcept_t *ei)
 {
     TRACE("\n");
-    return error_constr(ctx, flags, dp, retv, ei, ctx->syntax_error_constr);
+    return error_constr(ctx, flags, argc, argv, retv, ei, ctx->syntax_error_constr);
 }
 
 static HRESULT TypeErrorConstr_value(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags,
-        DISPPARAMS *dp, VARIANT *retv, jsexcept_t *ei)
+        unsigned argc, VARIANT *argv, VARIANT *retv, jsexcept_t *ei)
 {
     TRACE("\n");
-    return error_constr(ctx, flags, dp, retv, ei, ctx->type_error_constr);
+    return error_constr(ctx, flags, argc, argv, retv, ei, ctx->type_error_constr);
 }
 
 static HRESULT URIErrorConstr_value(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags,
-        DISPPARAMS *dp, VARIANT *retv, jsexcept_t *ei)
+        unsigned argc, VARIANT *argv, VARIANT *retv, jsexcept_t *ei)
 {
     TRACE("\n");
-    return error_constr(ctx, flags, dp, retv, ei, ctx->uri_error_constr);
+    return error_constr(ctx, flags, argc, argv, retv, ei, ctx->uri_error_constr);
 }
 
 HRESULT init_error_constr(script_ctx_t *ctx, jsdisp_t *object_prototype)
diff --git a/dlls/jscript/function.c b/dlls/jscript/function.c
index 5cde865725b..618831b4a97 100644
--- a/dlls/jscript/function.c
+++ b/dlls/jscript/function.c
@@ -55,37 +55,18 @@ static const WCHAR applyW[] = {'a','p','p','l','y',0};
 static const WCHAR callW[] = {'c','a','l','l',0};
 static const WCHAR argumentsW[] = {'a','r','g','u','m','e','n','t','s',0};
 
-static IDispatch *get_this(DISPPARAMS *dp)
-{
-    DWORD i;
-
-    for(i=0; i < dp->cNamedArgs; i++) {
-        if(dp->rgdispidNamedArgs[i] == DISPID_THIS) {
-            if(V_VT(dp->rgvarg+i) == VT_DISPATCH)
-                return V_DISPATCH(dp->rgvarg+i);
-
-            WARN("This is not VT_DISPATCH\n");
-            return NULL;
-        }
-    }
-
-    TRACE("no this passed\n");
-    return NULL;
-}
-
-static HRESULT init_parameters(jsdisp_t *var_disp, FunctionInstance *function, DISPPARAMS *dp,
+static HRESULT init_parameters(jsdisp_t *var_disp, FunctionInstance *function, unsigned argc, VARIANT *argv,
         jsexcept_t *ei)
 {
     VARIANT var_empty;
-    DWORD cargs, i=0;
+    DWORD i=0;
     HRESULT hres;
 
     V_VT(&var_empty) = VT_EMPTY;
-    cargs = arg_cnt(dp);
 
     for(i=0; i < function->func_code->param_cnt; i++) {
         hres = jsdisp_propput_name(var_disp, function->func_code->params[i],
-                i < cargs ? get_arg(dp,i) : &var_empty, ei);
+                i < argc ? argv+i : &var_empty, ei);
         if(FAILED(hres))
             return hres;
     }
@@ -93,7 +74,7 @@ static HRESULT init_parameters(jsdisp_t *var_disp, FunctionInstance *function, D
     return S_OK;
 }
 
-static HRESULT Arguments_value(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Arguments_value(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     FIXME("\n");
@@ -108,7 +89,7 @@ static const builtin_info_t Arguments_info = {
     NULL
 };
 
-static HRESULT create_arguments(script_ctx_t *ctx, IDispatch *calee, DISPPARAMS *dp,
+static HRESULT create_arguments(script_ctx_t *ctx, IDispatch *calee, unsigned argc, VARIANT *argv,
         jsexcept_t *ei, jsdisp_t **ret)
 {
     jsdisp_t *args;
@@ -128,14 +109,14 @@ static HRESULT create_arguments(script_ctx_t *ctx, IDispatch *calee, DISPPARAMS
         return hres;
     }
 
-    for(i=0; i < arg_cnt(dp); i++) {
-        hres = jsdisp_propput_idx(args, i, get_arg(dp,i), ei);
+    for(i=0; i < argc; i++) {
+        hres = jsdisp_propput_idx(args, i, argv+i, ei);
         if(FAILED(hres))
             break;
     }
 
     if(SUCCEEDED(hres)) {
-        num_set_int(&var, arg_cnt(dp));
+        num_set_int(&var, argc);
         hres = jsdisp_propput_name(args, lengthW, &var, ei);
 
         if(SUCCEEDED(hres)) {
@@ -155,7 +136,7 @@ static HRESULT create_arguments(script_ctx_t *ctx, IDispatch *calee, DISPPARAMS
 }
 
 static HRESULT create_var_disp(script_ctx_t *ctx, FunctionInstance *function, jsdisp_t *arg_disp,
-        DISPPARAMS *dp, jsexcept_t *ei, jsdisp_t **ret)
+        unsigned argc, VARIANT *argv, jsexcept_t *ei, jsdisp_t **ret)
 {
     jsdisp_t *var_disp;
     VARIANT var;
@@ -168,7 +149,7 @@ static HRESULT create_var_disp(script_ctx_t *ctx, FunctionInstance *function, js
     var_set_jsdisp(&var, arg_disp);
     hres = jsdisp_propput_name(var_disp, argumentsW, &var, ei);
     if(SUCCEEDED(hres))
-        hres = init_parameters(var_disp, function, dp, ei);
+        hres = init_parameters(var_disp, function, argc, argv, ei);
     if(FAILED(hres)) {
         jsdisp_release(var_disp);
         return hres;
@@ -178,7 +159,7 @@ static HRESULT create_var_disp(script_ctx_t *ctx, FunctionInstance *function, js
     return S_OK;
 }
 
-static HRESULT invoke_source(script_ctx_t *ctx, FunctionInstance *function, IDispatch *this_obj, DISPPARAMS *dp,
+static HRESULT invoke_source(script_ctx_t *ctx, FunctionInstance *function, IDispatch *this_obj, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     jsdisp_t *var_disp, *arg_disp;
@@ -191,11 +172,11 @@ static HRESULT invoke_source(script_ctx_t *ctx, FunctionInstance *function, IDis
         return E_FAIL;
     }
 
-    hres = create_arguments(ctx, to_disp(&function->dispex), dp, ei, &arg_disp);
+    hres = create_arguments(ctx, to_disp(&function->dispex), argc, argv, ei, &arg_disp);
     if(FAILED(hres))
         return hres;
 
-    hres = create_var_disp(ctx, function, arg_disp, dp, ei, &var_disp);
+    hres = create_var_disp(ctx, function, arg_disp, argc, argv, ei, &var_disp);
     if(FAILED(hres)) {
         jsdisp_release(arg_disp);
         return hres;
@@ -222,7 +203,7 @@ static HRESULT invoke_source(script_ctx_t *ctx, FunctionInstance *function, IDis
     return hres;
 }
 
-static HRESULT invoke_constructor(script_ctx_t *ctx, FunctionInstance *function, DISPPARAMS *dp,
+static HRESULT invoke_constructor(script_ctx_t *ctx, FunctionInstance *function, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     jsdisp_t *this_obj;
@@ -233,7 +214,7 @@ static HRESULT invoke_constructor(script_ctx_t *ctx, FunctionInstance *function,
     if(FAILED(hres))
         return hres;
 
-    hres = invoke_source(ctx, function, to_disp(this_obj), dp, &var, ei);
+    hres = invoke_source(ctx, function, to_disp(this_obj), argc, argv, &var, ei);
     if(FAILED(hres)) {
         jsdisp_release(this_obj);
         return hres;
@@ -250,7 +231,7 @@ static HRESULT invoke_constructor(script_ctx_t *ctx, FunctionInstance *function,
     return S_OK;
 }
 
-static HRESULT invoke_value_proc(script_ctx_t *ctx, FunctionInstance *function, IDispatch *this_disp, WORD flags, DISPPARAMS *dp,
+static HRESULT invoke_value_proc(script_ctx_t *ctx, FunctionInstance *function, IDispatch *this_disp, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     vdisp_t vthis;
@@ -263,19 +244,19 @@ static HRESULT invoke_value_proc(script_ctx_t *ctx, FunctionInstance *function,
     else
         set_jsdisp(&vthis, ctx->global);
 
-    hres = function->value_proc(ctx, &vthis, flags, dp, retv, ei);
+    hres = function->value_proc(ctx, &vthis, flags, argc, argv, retv, ei);
 
     vdisp_release(&vthis);
     return hres;
 }
 
-static HRESULT call_function(script_ctx_t *ctx, FunctionInstance *function, IDispatch *this_obj, DISPPARAMS *args,
-        VARIANT *retv, jsexcept_t *ei)
+static HRESULT call_function(script_ctx_t *ctx, FunctionInstance *function, IDispatch *this_obj,
+        unsigned argc, VARIANT *argv, VARIANT *retv, jsexcept_t *ei)
 {
     if(function->value_proc)
-        return invoke_value_proc(ctx, function, this_obj, DISPATCH_METHOD, args, retv, ei);
+        return invoke_value_proc(ctx, function, this_obj, DISPATCH_METHOD, argc, argv, retv, ei);
 
-    return invoke_source(ctx, function, this_obj, args, retv, ei);
+    return invoke_source(ctx, function, this_obj, argc, argv, retv, ei);
 }
 
 static HRESULT function_to_string(FunctionInstance *function, BSTR *ret)
@@ -307,7 +288,7 @@ static HRESULT function_to_string(FunctionInstance *function, BSTR *ret)
     return S_OK;
 }
 
-HRESULT Function_invoke(jsdisp_t *func_this, IDispatch *jsthis, WORD flags, DISPPARAMS *dp, VARIANT *retv, jsexcept_t *ei)
+HRESULT Function_invoke(jsdisp_t *func_this, IDispatch *jsthis, WORD flags, unsigned argc, VARIANT *argv, VARIANT *retv, jsexcept_t *ei)
 {
     FunctionInstance *function;
 
@@ -317,16 +298,16 @@ HRESULT Function_invoke(jsdisp_t *func_this, IDispatch *jsthis, WORD flags, DISP
     function = (FunctionInstance*)func_this;
 
     if(function->value_proc)
-        return invoke_value_proc(function->dispex.ctx, function, jsthis, flags, dp, retv, ei);
+        return invoke_value_proc(function->dispex.ctx, function, jsthis, flags, argc, argv, retv, ei);
 
     if(flags == DISPATCH_CONSTRUCT)
-        return invoke_constructor(function->dispex.ctx, function, dp, retv, ei);
+        return invoke_constructor(function->dispex.ctx, function, argc, argv, retv, ei);
 
     assert(flags == DISPATCH_METHOD);
-    return invoke_source(function->dispex.ctx, function, jsthis, dp, retv, ei);
+    return invoke_source(function->dispex.ctx, function, jsthis, argc, argv, retv, ei);
 }
 
-static HRESULT Function_length(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Function_length(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     FunctionInstance *This = function_from_vdisp(jsthis);
@@ -345,7 +326,7 @@ static HRESULT Function_length(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, D
     return S_OK;
 }
 
-static HRESULT Function_toString(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Function_toString(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     FunctionInstance *function;
@@ -370,7 +351,7 @@ static HRESULT Function_toString(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags,
     return S_OK;
 }
 
-static HRESULT array_to_args(script_ctx_t *ctx, jsdisp_t *arg_array, jsexcept_t *ei, DISPPARAMS *args)
+static HRESULT array_to_args(script_ctx_t *ctx, jsdisp_t *arg_array, jsexcept_t *ei, unsigned *argc, VARIANT **ret)
 {
     VARIANT var, *argv;
     DWORD length, i;
@@ -401,17 +382,17 @@ static HRESULT array_to_args(script_ctx_t *ctx, jsdisp_t *arg_array, jsexcept_t
         }
     }
 
-    args->cArgs = length;
-    args->rgvarg = argv;
+    *argc = length;
+    *ret = argv;
     return S_OK;
 }
 
-static HRESULT Function_apply(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Function_apply(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     FunctionInstance *function;
-    DISPPARAMS args = {NULL,NULL,0,0};
-    DWORD argc, i;
+    VARIANT *args = NULL;
+    unsigned i, cnt = 0;
     IDispatch *this_obj = NULL;
     HRESULT hres = S_OK;
 
@@ -420,12 +401,9 @@ static HRESULT Function_apply(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DI
     if(!(function = function_this(jsthis)))
         return throw_type_error(ctx, ei, JS_E_FUNCTION_EXPECTED, NULL);
 
-    argc = arg_cnt(dp);
     if(argc) {
-        VARIANT *v = get_arg(dp,0);
-
-        if(V_VT(v) != VT_EMPTY && V_VT(v) != VT_NULL) {
-            hres = to_object(ctx, v, &this_obj);
+        if(V_VT(argv) != VT_EMPTY && V_VT(argv) != VT_NULL) {
+            hres = to_object(ctx, argv, &this_obj);
             if(FAILED(hres))
                 return hres;
         }
@@ -434,8 +412,8 @@ static HRESULT Function_apply(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DI
     if(argc >= 2) {
         jsdisp_t *arg_array = NULL;
 
-        if(V_VT(get_arg(dp,1)) == VT_DISPATCH) {
-            arg_array = iface_to_jsdisp((IUnknown*)V_DISPATCH(get_arg(dp,1)));
+        if(V_VT(argv+1) == VT_DISPATCH) {
+            arg_array = iface_to_jsdisp((IUnknown*)V_DISPATCH(argv+1));
             if(arg_array &&
                (!is_class(arg_array, JSCLASS_ARRAY) && !is_class(arg_array, JSCLASS_ARGUMENTS) )) {
                 jsdisp_release(arg_array);
@@ -444,7 +422,7 @@ static HRESULT Function_apply(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DI
         }
 
         if(arg_array) {
-            hres = array_to_args(ctx, arg_array, ei, &args);
+            hres = array_to_args(ctx, arg_array, ei, &cnt, &args);
             jsdisp_release(arg_array);
         }else {
             FIXME("throw TypeError\n");
@@ -453,23 +431,22 @@ static HRESULT Function_apply(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DI
     }
 
     if(SUCCEEDED(hres))
-       hres = call_function(ctx, function, this_obj, &args, retv, ei);
+        hres = call_function(ctx, function, this_obj, cnt, args, retv, ei);
 
     if(this_obj)
         IDispatch_Release(this_obj);
-    for(i=0; i<args.cArgs; i++)
-        VariantClear(args.rgvarg+i);
-    heap_free(args.rgvarg);
+    for(i=0; i < cnt; i++)
+        VariantClear(args+i);
+    heap_free(args);
     return hres;
 }
 
-static HRESULT Function_call(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Function_call(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     FunctionInstance *function;
-    DISPPARAMS args = {NULL,NULL,0,0};
     IDispatch *this_obj = NULL;
-    DWORD argc;
+    unsigned cnt = 0;
     HRESULT hres;
 
     TRACE("\n");
@@ -477,30 +454,24 @@ static HRESULT Function_call(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DIS
     if(!(function = function_this(jsthis)))
         return throw_type_error(ctx, ei, JS_E_FUNCTION_EXPECTED, NULL);
 
-    argc = arg_cnt(dp);
     if(argc) {
-        VARIANT *v = get_arg(dp,0);
-
-        if(V_VT(v) != VT_EMPTY && V_VT(v) != VT_NULL) {
-            hres = to_object(ctx, v, &this_obj);
+        if(V_VT(argv) != VT_EMPTY && V_VT(argv) != VT_NULL) {
+            hres = to_object(ctx, argv, &this_obj);
             if(FAILED(hres))
                 return hres;
         }
 
-        args.cArgs = argc-1;
+        cnt = argc-1;
     }
 
-    if(args.cArgs)
-        args.rgvarg = dp->rgvarg + dp->cArgs - args.cArgs-1;
-
-    hres = call_function(ctx, function, this_obj, &args, retv, ei);
+    hres = call_function(ctx, function, this_obj, cnt, argv+1, retv, ei);
 
     if(this_obj)
         IDispatch_Release(this_obj);
     return hres;
 }
 
-HRESULT Function_value(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+HRESULT Function_value(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     FunctionInstance *function;
@@ -516,10 +487,8 @@ HRESULT Function_value(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAM
 
     switch(flags) {
     case DISPATCH_METHOD:
-        if(function->value_proc)
-            return invoke_value_proc(ctx, function, get_this(dp), flags, dp, retv, ei);
-
-        return invoke_source(ctx, function, get_this(dp), dp, retv, ei);
+        assert(function->value_proc != NULL);
+        return invoke_value_proc(ctx, function, NULL, flags, argc, argv, retv, ei);
 
     case DISPATCH_PROPERTYGET: {
         HRESULT hres;
@@ -535,10 +504,8 @@ HRESULT Function_value(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAM
     }
 
     case DISPATCH_CONSTRUCT:
-        if(function->value_proc)
-            return invoke_value_proc(ctx, function, get_this(dp), flags, dp, retv, ei);
-
-        return invoke_constructor(ctx, function, dp, retv, ei);
+        assert(function->value_proc != NULL);
+        return invoke_value_proc(ctx, function, NULL, flags, argc, argv, retv, ei);
 
     default:
         FIXME("not implemented flags %x\n", flags);
@@ -549,7 +516,7 @@ HRESULT Function_value(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAM
 }
 
 static HRESULT Function_arguments(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags,
-        DISPPARAMS *dp, VARIANT *retv, jsexcept_t *ei)
+        unsigned argc, VARIANT *argv, VARIANT *retv, jsexcept_t *ei)
 {
     FunctionInstance *function = (FunctionInstance*)jsthis->u.jsdisp;
     HRESULT hres = S_OK;
@@ -707,10 +674,10 @@ HRESULT create_source_function(script_ctx_t *ctx, bytecode_t *code, function_cod
     return S_OK;
 }
 
-static HRESULT construct_function(script_ctx_t *ctx, DISPPARAMS *dp, jsexcept_t *ei, IDispatch **ret)
+static HRESULT construct_function(script_ctx_t *ctx, unsigned argc, VARIANT *argv, jsexcept_t *ei, IDispatch **ret)
 {
     WCHAR *str = NULL, *ptr;
-    DWORD argc, len = 0, l;
+    DWORD len = 0, l;
     bytecode_t *code;
     jsdisp_t *function;
     BSTR *params = NULL;
@@ -721,7 +688,6 @@ static HRESULT construct_function(script_ctx_t *ctx, DISPPARAMS *dp, jsexcept_t
     static const WCHAR function_beginW[] = {')',' ','{','\n'};
     static const WCHAR function_endW[] = {'\n','}',0};
 
-    argc = arg_cnt(dp);
     if(argc) {
         params = heap_alloc(argc*sizeof(BSTR));
         if(!params)
@@ -730,7 +696,7 @@ static HRESULT construct_function(script_ctx_t *ctx, DISPPARAMS *dp, jsexcept_t
         if(argc > 2)
             len = (argc-2)*2; /* separating commas */
         for(i=0; i < argc; i++) {
-            hres = to_string(ctx, get_arg(dp,i), ei, params+i);
+            hres = to_string(ctx, argv+i, ei, params+i);
             if(FAILED(hres))
                 break;
             len += SysStringLen(params[i]);
@@ -795,7 +761,7 @@ static HRESULT construct_function(script_ctx_t *ctx, DISPPARAMS *dp, jsexcept_t
     return S_OK;
 }
 
-static HRESULT FunctionConstr_value(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT FunctionConstr_value(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     HRESULT hres;
@@ -806,7 +772,7 @@ static HRESULT FunctionConstr_value(script_ctx_t *ctx, vdisp_t *jsthis, WORD fla
     case DISPATCH_CONSTRUCT: {
         IDispatch *ret;
 
-        hres = construct_function(ctx, dp, ei, &ret);
+        hres = construct_function(ctx, argc, argv, ei, &ret);
         if(FAILED(hres))
             return hres;
 
@@ -822,7 +788,7 @@ static HRESULT FunctionConstr_value(script_ctx_t *ctx, vdisp_t *jsthis, WORD fla
     return S_OK;
 }
 
-static HRESULT FunctionProt_value(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT FunctionProt_value(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     FIXME("\n");
diff --git a/dlls/jscript/global.c b/dlls/jscript/global.c
index ce1c5411823..f50debf63a1 100644
--- a/dlls/jscript/global.c
+++ b/dlls/jscript/global.c
@@ -113,161 +113,161 @@ static WCHAR int_to_char(int i)
     return 'A'+i-10;
 }
 
-static HRESULT constructor_call(jsdisp_t *constr, WORD flags, DISPPARAMS *dp,
+static HRESULT constructor_call(jsdisp_t *constr, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     if(flags != DISPATCH_PROPERTYGET)
-        return jsdisp_call_value(constr, NULL, flags, dp, retv, ei);
+        return jsdisp_call_value(constr, NULL, flags, argc, argv, retv, ei);
 
     jsdisp_addref(constr);
     var_set_jsdisp(retv, constr);
     return S_OK;
 }
 
-static HRESULT JSGlobal_Array(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT JSGlobal_Array(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     TRACE("\n");
 
-    return constructor_call(ctx->array_constr, flags, dp, retv, ei);
+    return constructor_call(ctx->array_constr, flags, argc, argv, retv, ei);
 }
 
-static HRESULT JSGlobal_Boolean(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT JSGlobal_Boolean(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     TRACE("\n");
 
-    return constructor_call(ctx->bool_constr, flags, dp, retv, ei);
+    return constructor_call(ctx->bool_constr, flags, argc, argv, retv, ei);
 }
 
-static HRESULT JSGlobal_Date(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT JSGlobal_Date(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     TRACE("\n");
 
-    return constructor_call(ctx->date_constr, flags, dp, retv, ei);
+    return constructor_call(ctx->date_constr, flags, argc, argv, retv, ei);
 }
 
-static HRESULT JSGlobal_Error(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT JSGlobal_Error(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     TRACE("\n");
 
-    return constructor_call(ctx->error_constr, flags, dp, retv, ei);
+    return constructor_call(ctx->error_constr, flags, argc, argv, retv, ei);
 }
 
-static HRESULT JSGlobal_EvalError(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT JSGlobal_EvalError(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     TRACE("\n");
 
-    return constructor_call(ctx->eval_error_constr, flags, dp, retv, ei);
+    return constructor_call(ctx->eval_error_constr, flags, argc, argv, retv, ei);
 }
 
-static HRESULT JSGlobal_RangeError(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT JSGlobal_RangeError(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     TRACE("\n");
 
-    return constructor_call(ctx->range_error_constr, flags, dp, retv, ei);
+    return constructor_call(ctx->range_error_constr, flags, argc, argv, retv, ei);
 }
 
-static HRESULT JSGlobal_ReferenceError(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT JSGlobal_ReferenceError(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     TRACE("\n");
 
-    return constructor_call(ctx->reference_error_constr, flags, dp, retv, ei);
+    return constructor_call(ctx->reference_error_constr, flags, argc, argv, retv, ei);
 }
 
-static HRESULT JSGlobal_SyntaxError(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT JSGlobal_SyntaxError(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     TRACE("\n");
 
-    return constructor_call(ctx->syntax_error_constr, flags, dp, retv, ei);
+    return constructor_call(ctx->syntax_error_constr, flags, argc, argv, retv, ei);
 }
 
-static HRESULT JSGlobal_TypeError(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT JSGlobal_TypeError(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     TRACE("\n");
 
-    return constructor_call(ctx->type_error_constr, flags, dp, retv, ei);
+    return constructor_call(ctx->type_error_constr, flags, argc, argv, retv, ei);
 }
 
-static HRESULT JSGlobal_URIError(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT JSGlobal_URIError(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     TRACE("\n");
 
-    return constructor_call(ctx->uri_error_constr, flags, dp, retv, ei);
+    return constructor_call(ctx->uri_error_constr, flags, argc, argv, retv, ei);
 }
 
-static HRESULT JSGlobal_Function(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT JSGlobal_Function(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     TRACE("\n");
 
-    return constructor_call(ctx->function_constr, flags, dp, retv, ei);
+    return constructor_call(ctx->function_constr, flags, argc, argv, retv, ei);
 }
 
-static HRESULT JSGlobal_Number(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT JSGlobal_Number(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     TRACE("\n");
 
-    return constructor_call(ctx->number_constr, flags, dp, retv, ei);
+    return constructor_call(ctx->number_constr, flags, argc, argv, retv, ei);
 }
 
-static HRESULT JSGlobal_Object(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT JSGlobal_Object(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     TRACE("\n");
 
-    return constructor_call(ctx->object_constr, flags, dp, retv, ei);
+    return constructor_call(ctx->object_constr, flags, argc, argv, retv, ei);
 }
 
-static HRESULT JSGlobal_String(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT JSGlobal_String(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     TRACE("\n");
 
-    return constructor_call(ctx->string_constr, flags, dp, retv, ei);
+    return constructor_call(ctx->string_constr, flags, argc, argv, retv, ei);
 }
 
-static HRESULT JSGlobal_RegExp(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT JSGlobal_RegExp(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     TRACE("\n");
 
-    return constructor_call(ctx->regexp_constr, flags, dp, retv, ei);
+    return constructor_call(ctx->regexp_constr, flags, argc, argv, retv, ei);
 }
 
-static HRESULT JSGlobal_ActiveXObject(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT JSGlobal_ActiveXObject(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     TRACE("\n");
 
-    return constructor_call(ctx->activex_constr, flags, dp, retv, ei);
+    return constructor_call(ctx->activex_constr, flags, argc, argv, retv, ei);
 }
 
-static HRESULT JSGlobal_VBArray(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT JSGlobal_VBArray(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     TRACE("\n");
 
-    return constructor_call(ctx->vbarray_constr, flags, dp, retv, ei);
+    return constructor_call(ctx->vbarray_constr, flags, argc, argv, retv, ei);
 }
 
-static HRESULT JSGlobal_Enumerator(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT JSGlobal_Enumerator(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     FIXME("\n");
     return E_NOTIMPL;
 }
 
-static HRESULT JSGlobal_escape(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT JSGlobal_escape(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     BSTR ret, str;
@@ -277,7 +277,7 @@ static HRESULT JSGlobal_escape(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, D
 
     TRACE("\n");
 
-    if(!arg_cnt(dp)) {
+    if(!argc) {
         if(retv) {
             ret = SysAllocString(undefinedW);
             if(!ret)
@@ -290,7 +290,7 @@ static HRESULT JSGlobal_escape(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, D
         return S_OK;
     }
 
-    hres = to_string(ctx, get_arg(dp, 0), ei, &str);
+    hres = to_string(ctx, argv, ei, &str);
     if(FAILED(hres))
         return hres;
 
@@ -341,26 +341,24 @@ static HRESULT JSGlobal_escape(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, D
 }
 
 /* ECMA-262 3rd Edition    15.1.2.1 */
-static HRESULT JSGlobal_eval(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT JSGlobal_eval(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     bytecode_t *code;
-    VARIANT *arg;
     HRESULT hres;
 
     TRACE("\n");
 
-    if(!arg_cnt(dp)) {
+    if(!argc) {
         if(retv)
             V_VT(retv) = VT_EMPTY;
         return S_OK;
     }
 
-    arg = get_arg(dp, 0);
-    if(V_VT(arg) != VT_BSTR) {
+    if(V_VT(argv) != VT_BSTR) {
         if(retv) {
             V_VT(retv) = VT_EMPTY;
-            return VariantCopy(retv, arg);
+            return VariantCopy(retv, argv);
         }
         return S_OK;
     }
@@ -370,10 +368,10 @@ static HRESULT JSGlobal_eval(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DIS
         return E_UNEXPECTED;
     }
 
-    TRACE("parsing %s\n", debugstr_w(V_BSTR(arg)));
-    hres = compile_script(ctx, V_BSTR(arg), NULL, TRUE, FALSE, &code);
+    TRACE("parsing %s\n", debugstr_w(V_BSTR(argv)));
+    hres = compile_script(ctx, V_BSTR(argv), NULL, TRUE, FALSE, &code);
     if(FAILED(hres)) {
-        WARN("parse (%s) failed: %08x\n", debugstr_w(V_BSTR(arg)), hres);
+        WARN("parse (%s) failed: %08x\n", debugstr_w(V_BSTR(argv)), hres);
         return throw_syntax_error(ctx, ei, hres, NULL);
     }
 
@@ -383,7 +381,7 @@ static HRESULT JSGlobal_eval(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DIS
     return hres;
 }
 
-static HRESULT JSGlobal_isNaN(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT JSGlobal_isNaN(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     VARIANT_BOOL ret = VARIANT_TRUE;
@@ -392,8 +390,8 @@ static HRESULT JSGlobal_isNaN(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DI
 
     TRACE("\n");
 
-    if(arg_cnt(dp)) {
-        hres = to_number(ctx, get_arg(dp,0), ei, &n);
+    if(argc) {
+        hres = to_number(ctx, argv, ei, &n);
         if(FAILED(hres))
             return hres;
 
@@ -408,7 +406,7 @@ static HRESULT JSGlobal_isNaN(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DI
     return S_OK;
 }
 
-static HRESULT JSGlobal_isFinite(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT JSGlobal_isFinite(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     VARIANT_BOOL ret = VARIANT_FALSE;
@@ -416,10 +414,10 @@ static HRESULT JSGlobal_isFinite(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags,
 
     TRACE("\n");
 
-    if(arg_cnt(dp)) {
+    if(argc) {
         double n;
 
-        hres = to_number(ctx, get_arg(dp,0), ei, &n);
+        hres = to_number(ctx, argv, ei, &n);
         if(FAILED(hres))
             return hres;
 
@@ -445,7 +443,7 @@ static INT char_to_int(WCHAR c)
     return 100;
 }
 
-static HRESULT JSGlobal_parseInt(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT JSGlobal_parseInt(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     BOOL neg = FALSE, empty = TRUE;
@@ -455,13 +453,13 @@ static HRESULT JSGlobal_parseInt(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags,
     BSTR str;
     HRESULT hres;
 
-    if(!arg_cnt(dp)) {
+    if(!argc) {
         if(retv) num_set_val(retv, NAN);
         return S_OK;
     }
 
-    if(arg_cnt(dp) >= 2) {
-        hres = to_int32(ctx, get_arg(dp, 1), ei, &radix);
+    if(argc >= 2) {
+        hres = to_int32(ctx, argv+1, ei, &radix);
         if(FAILED(hres))
             return hres;
 
@@ -473,7 +471,7 @@ static HRESULT JSGlobal_parseInt(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags,
         }
     }
 
-    hres = to_string(ctx, get_arg(dp, 0), ei, &str);
+    hres = to_string(ctx, argv, ei, &str);
     if(FAILED(hres))
         return hres;
 
@@ -524,25 +522,23 @@ static HRESULT JSGlobal_parseInt(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags,
     return S_OK;
 }
 
-static HRESULT JSGlobal_parseFloat(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT JSGlobal_parseFloat(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     LONGLONG d = 0, hlp;
     int exp = 0;
-    VARIANT *arg;
     WCHAR *str;
     BSTR val_str = NULL;
     BOOL ret_nan = TRUE, positive = TRUE;
     HRESULT hres;
 
-    if(!arg_cnt(dp)) {
+    if(!argc) {
         if(retv)
             num_set_val(retv, NAN);
         return S_OK;
     }
 
-    arg = get_arg(dp, 0);
-    hres = to_string(ctx, arg, ei, &val_str);
+    hres = to_string(ctx, argv, ei, &val_str);
     if(FAILED(hres))
         return hres;
 
@@ -633,7 +629,7 @@ static inline int hex_to_int(const WCHAR wch) {
     return -1;
 }
 
-static HRESULT JSGlobal_unescape(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT JSGlobal_unescape(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     BSTR ret, str;
@@ -643,7 +639,7 @@ static HRESULT JSGlobal_unescape(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags,
 
     TRACE("\n");
 
-    if(!arg_cnt(dp)) {
+    if(!argc) {
         if(retv) {
             ret = SysAllocString(undefinedW);
             if(!ret)
@@ -656,7 +652,7 @@ static HRESULT JSGlobal_unescape(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags,
         return S_OK;
     }
 
-    hres = to_string(ctx, get_arg(dp, 0), ei, &str);
+    hres = to_string(ctx, argv, ei, &str);
     if(FAILED(hres))
         return hres;
 
@@ -712,14 +708,14 @@ static HRESULT JSGlobal_unescape(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags,
     return S_OK;
 }
 
-static HRESULT JSGlobal_GetObject(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT JSGlobal_GetObject(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     FIXME("\n");
     return E_NOTIMPL;
 }
 
-static HRESULT JSGlobal_ScriptEngine(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT JSGlobal_ScriptEngine(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     static const WCHAR JScriptW[] = {'J','S','c','r','i','p','t',0};
@@ -740,7 +736,7 @@ static HRESULT JSGlobal_ScriptEngine(script_ctx_t *ctx, vdisp_t *jsthis, WORD fl
     return S_OK;
 }
 
-static HRESULT JSGlobal_ScriptEngineMajorVersion(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT JSGlobal_ScriptEngineMajorVersion(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     TRACE("\n");
@@ -750,7 +746,7 @@ static HRESULT JSGlobal_ScriptEngineMajorVersion(script_ctx_t *ctx, vdisp_t *jst
     return S_OK;
 }
 
-static HRESULT JSGlobal_ScriptEngineMinorVersion(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT JSGlobal_ScriptEngineMinorVersion(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     TRACE("\n");
@@ -760,7 +756,7 @@ static HRESULT JSGlobal_ScriptEngineMinorVersion(script_ctx_t *ctx, vdisp_t *jst
     return S_OK;
 }
 
-static HRESULT JSGlobal_ScriptEngineBuildVersion(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT JSGlobal_ScriptEngineBuildVersion(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     TRACE("\n");
@@ -770,14 +766,14 @@ static HRESULT JSGlobal_ScriptEngineBuildVersion(script_ctx_t *ctx, vdisp_t *jst
     return S_OK;
 }
 
-static HRESULT JSGlobal_CollectGarbage(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT JSGlobal_CollectGarbage(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     FIXME("\n");
     return E_NOTIMPL;
 }
 
-static HRESULT JSGlobal_encodeURI(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT JSGlobal_encodeURI(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     const WCHAR *ptr;
@@ -789,7 +785,7 @@ static HRESULT JSGlobal_encodeURI(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags
 
     TRACE("\n");
 
-    if(!arg_cnt(dp)) {
+    if(!argc) {
         if(retv) {
             ret = SysAllocString(undefinedW);
             if(!ret)
@@ -802,7 +798,7 @@ static HRESULT JSGlobal_encodeURI(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags
         return S_OK;
     }
 
-    hres = to_string(ctx, get_arg(dp,0), ei, &str);
+    hres = to_string(ctx, argv, ei, &str);
     if(FAILED(hres))
         return hres;
 
@@ -851,7 +847,7 @@ static HRESULT JSGlobal_encodeURI(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags
     return S_OK;
 }
 
-static HRESULT JSGlobal_decodeURI(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT JSGlobal_decodeURI(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     BSTR str, ret;
@@ -863,7 +859,7 @@ static HRESULT JSGlobal_decodeURI(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags
 
     TRACE("\n");
 
-    if(!arg_cnt(dp)) {
+    if(!argc) {
         if(retv) {
             ret = SysAllocString(undefinedW);
             if(!ret)
@@ -876,7 +872,7 @@ static HRESULT JSGlobal_decodeURI(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags
         return S_OK;
     }
 
-    hres = to_string(ctx, get_arg(dp,0), ei, &str);
+    hres = to_string(ctx, argv, ei, &str);
     if(FAILED(hres))
         return hres;
 
@@ -947,7 +943,7 @@ static HRESULT JSGlobal_decodeURI(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags
     return S_OK;
 }
 
-static HRESULT JSGlobal_encodeURIComponent(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT JSGlobal_encodeURIComponent(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     BSTR str, ret;
@@ -958,7 +954,7 @@ static HRESULT JSGlobal_encodeURIComponent(script_ctx_t *ctx, vdisp_t *jsthis, W
 
     TRACE("\n");
 
-    if(!arg_cnt(dp)) {
+    if(!argc) {
         if(retv) {
             ret = SysAllocString(undefinedW);
             if(!ret)
@@ -971,7 +967,7 @@ static HRESULT JSGlobal_encodeURIComponent(script_ctx_t *ctx, vdisp_t *jsthis, W
         return S_OK;
     }
 
-    hres = to_string(ctx, get_arg(dp, 0), ei, &str);
+    hres = to_string(ctx, argv, ei, &str);
     if(FAILED(hres))
         return hres;
 
@@ -1021,7 +1017,7 @@ static HRESULT JSGlobal_encodeURIComponent(script_ctx_t *ctx, vdisp_t *jsthis, W
 }
 
 /* ECMA-262 3rd Edition    15.1.3.2 */
-static HRESULT JSGlobal_decodeURIComponent(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT JSGlobal_decodeURIComponent(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     BSTR str, ret;
@@ -1032,7 +1028,7 @@ static HRESULT JSGlobal_decodeURIComponent(script_ctx_t *ctx, vdisp_t *jsthis, W
 
     TRACE("\n");
 
-    if(!arg_cnt(dp)) {
+    if(!argc) {
         if(retv) {
             ret = SysAllocString(undefinedW);
             if(!ret)
@@ -1045,7 +1041,7 @@ static HRESULT JSGlobal_decodeURIComponent(script_ctx_t *ctx, vdisp_t *jsthis, W
         return S_OK;
     }
 
-    hres = to_string(ctx, get_arg(dp, 0), ei, &str);
+    hres = to_string(ctx, argv, ei, &str);
     if(FAILED(hres))
         return hres;
 
diff --git a/dlls/jscript/jscript.h b/dlls/jscript/jscript.h
index b1366518c2a..f36dcf33077 100644
--- a/dlls/jscript/jscript.h
+++ b/dlls/jscript/jscript.h
@@ -152,7 +152,7 @@ static inline jsdisp_t *get_jsdisp(vdisp_t *vdisp)
     return is_jsdisp(vdisp) ? vdisp->u.jsdisp : NULL;
 }
 
-typedef HRESULT (*builtin_invoke_t)(script_ctx_t*,vdisp_t*,WORD,DISPPARAMS*,VARIANT*,jsexcept_t*);
+typedef HRESULT (*builtin_invoke_t)(script_ctx_t*,vdisp_t*,WORD,unsigned,VARIANT*,VARIANT*,jsexcept_t*);
 
 typedef struct {
     const WCHAR *name;
@@ -206,11 +206,11 @@ HRESULT create_dispex(script_ctx_t*,const builtin_info_t*,jsdisp_t*,jsdisp_t**)
 HRESULT init_dispex(jsdisp_t*,script_ctx_t*,const builtin_info_t*,jsdisp_t*) DECLSPEC_HIDDEN;
 HRESULT init_dispex_from_constr(jsdisp_t*,script_ctx_t*,const builtin_info_t*,jsdisp_t*) DECLSPEC_HIDDEN;
 
-HRESULT disp_call(script_ctx_t*,IDispatch*,DISPID,WORD,DISPPARAMS*,VARIANT*,jsexcept_t*) DECLSPEC_HIDDEN;
-HRESULT disp_call_value(script_ctx_t*,IDispatch*,IDispatch*,WORD,DISPPARAMS*,VARIANT*,jsexcept_t*) DECLSPEC_HIDDEN;
-HRESULT jsdisp_call_value(jsdisp_t*,IDispatch*,WORD,DISPPARAMS*,VARIANT*,jsexcept_t*) DECLSPEC_HIDDEN;
-HRESULT jsdisp_call(jsdisp_t*,DISPID,WORD,DISPPARAMS*,VARIANT*,jsexcept_t*) DECLSPEC_HIDDEN;
-HRESULT jsdisp_call_name(jsdisp_t*,const WCHAR*,WORD,DISPPARAMS*,VARIANT*,jsexcept_t*) DECLSPEC_HIDDEN;
+HRESULT disp_call(script_ctx_t*,IDispatch*,DISPID,WORD,unsigned,VARIANT*,VARIANT*,jsexcept_t*) DECLSPEC_HIDDEN;
+HRESULT disp_call_value(script_ctx_t*,IDispatch*,IDispatch*,WORD,unsigned,VARIANT*,VARIANT*,jsexcept_t*) DECLSPEC_HIDDEN;
+HRESULT jsdisp_call_value(jsdisp_t*,IDispatch*,WORD,unsigned,VARIANT*,VARIANT*,jsexcept_t*) DECLSPEC_HIDDEN;
+HRESULT jsdisp_call(jsdisp_t*,DISPID,WORD,unsigned,VARIANT*,VARIANT*,jsexcept_t*) DECLSPEC_HIDDEN;
+HRESULT jsdisp_call_name(jsdisp_t*,const WCHAR*,WORD,unsigned,VARIANT*,VARIANT*,jsexcept_t*) DECLSPEC_HIDDEN;
 HRESULT disp_propget(script_ctx_t*,IDispatch*,DISPID,VARIANT*,jsexcept_t*) DECLSPEC_HIDDEN;
 HRESULT disp_propput(script_ctx_t*,IDispatch*,DISPID,VARIANT*,jsexcept_t*) DECLSPEC_HIDDEN;
 HRESULT jsdisp_propget(jsdisp_t*,DISPID,VARIANT*,jsexcept_t*) DECLSPEC_HIDDEN;
@@ -225,8 +225,8 @@ VARIANT_BOOL jsdisp_is_own_prop(jsdisp_t *obj, BSTR name) DECLSPEC_HIDDEN;
 
 HRESULT create_builtin_function(script_ctx_t*,builtin_invoke_t,const WCHAR*,const builtin_info_t*,DWORD,
         jsdisp_t*,jsdisp_t**) DECLSPEC_HIDDEN;
-HRESULT Function_value(script_ctx_t*,vdisp_t*,WORD,DISPPARAMS*,VARIANT*,jsexcept_t*) DECLSPEC_HIDDEN;
-HRESULT Function_invoke(jsdisp_t*,IDispatch*,WORD,DISPPARAMS*,VARIANT*,jsexcept_t*);
+HRESULT Function_value(script_ctx_t*,vdisp_t*,WORD,unsigned,VARIANT*,VARIANT*,jsexcept_t*) DECLSPEC_HIDDEN;
+HRESULT Function_invoke(jsdisp_t*,IDispatch*,WORD,unsigned,VARIANT*,VARIANT*,jsexcept_t*);
 
 HRESULT throw_eval_error(script_ctx_t*,jsexcept_t*,HRESULT,const WCHAR*) DECLSPEC_HIDDEN;
 HRESULT throw_generic_error(script_ctx_t*,jsexcept_t*,HRESULT,const WCHAR*) DECLSPEC_HIDDEN;
diff --git a/dlls/jscript/jsutils.c b/dlls/jscript/jsutils.c
index fbc82e7a2aa..0e8e3047c61 100644
--- a/dlls/jscript/jsutils.c
+++ b/dlls/jscript/jsutils.c
@@ -203,7 +203,6 @@ HRESULT to_primitive(script_ctx_t *ctx, VARIANT *v, jsexcept_t *ei, VARIANT *ret
     case VT_DISPATCH: {
         jsdisp_t *jsdisp;
         DISPID id;
-        DISPPARAMS dp = {NULL, NULL, 0, 0};
         HRESULT hres;
 
         static const WCHAR toStringW[] = {'t','o','S','t','r','i','n','g',0};
@@ -227,7 +226,7 @@ HRESULT to_primitive(script_ctx_t *ctx, VARIANT *v, jsexcept_t *ei, VARIANT *ret
 
         hres = jsdisp_get_id(jsdisp, hint == HINT_STRING ? toStringW : valueOfW, 0, &id);
         if(SUCCEEDED(hres)) {
-            hres = jsdisp_call(jsdisp, id, DISPATCH_METHOD, &dp, ret, ei);
+            hres = jsdisp_call(jsdisp, id, DISPATCH_METHOD, 0, NULL, ret, ei);
             if(FAILED(hres)) {
                 WARN("call error - forwarding exception\n");
                 jsdisp_release(jsdisp);
@@ -243,7 +242,7 @@ HRESULT to_primitive(script_ctx_t *ctx, VARIANT *v, jsexcept_t *ei, VARIANT *ret
 
         hres = jsdisp_get_id(jsdisp, hint == HINT_STRING ? valueOfW : toStringW, 0, &id);
         if(SUCCEEDED(hres)) {
-            hres = jsdisp_call(jsdisp, id, DISPATCH_METHOD, &dp, ret, ei);
+            hres = jsdisp_call(jsdisp, id, DISPATCH_METHOD, 0, NULL, ret, ei);
             if(FAILED(hres)) {
                 WARN("call error - forwarding exception\n");
                 jsdisp_release(jsdisp);
diff --git a/dlls/jscript/math.c b/dlls/jscript/math.c
index d0eab57fc88..658ce7b9c12 100644
--- a/dlls/jscript/math.c
+++ b/dlls/jscript/math.c
@@ -58,7 +58,7 @@ static const WCHAR sqrtW[] = {'s','q','r','t',0};
 static const WCHAR tanW[] = {'t','a','n',0};
 
 /* ECMA-262 3rd Edition    15.8.2.12 */
-static HRESULT Math_abs(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Math_abs(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     double d;
@@ -66,13 +66,13 @@ static HRESULT Math_abs(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARA
 
     TRACE("\n");
 
-    if(!arg_cnt(dp)) {
+    if(!argc) {
         if(retv)
             num_set_val(retv, NAN);
         return S_OK;
     }
 
-    hres = to_number(ctx, get_arg(dp, 0), ei, &d);
+    hres = to_number(ctx, argv, ei, &d);
     if(FAILED(hres))
         return hres;
 
@@ -81,7 +81,7 @@ static HRESULT Math_abs(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARA
     return S_OK;
 }
 
-static HRESULT Math_acos(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Math_acos(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     double x;
@@ -89,12 +89,12 @@ static HRESULT Math_acos(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPAR
 
     TRACE("\n");
 
-    if(!arg_cnt(dp)) {
+    if(!argc) {
         if(retv) num_set_val(retv, NAN);
         return S_OK;
     }
 
-    hres = to_number(ctx, get_arg(dp, 0), ei, &x);
+    hres = to_number(ctx, argv, ei, &x);
     if(FAILED(hres))
         return hres;
 
@@ -103,7 +103,7 @@ static HRESULT Math_acos(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPAR
     return S_OK;
 }
 
-static HRESULT Math_asin(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Math_asin(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     double x;
@@ -111,12 +111,12 @@ static HRESULT Math_asin(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPAR
 
     TRACE("\n");
 
-    if(!arg_cnt(dp)) {
+    if(!argc) {
         if(retv) num_set_val(retv, NAN);
         return S_OK;
     }
 
-    hres = to_number(ctx, get_arg(dp, 0), ei, &x);
+    hres = to_number(ctx, argv, ei, &x);
     if(FAILED(hres))
         return hres;
 
@@ -125,7 +125,7 @@ static HRESULT Math_asin(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPAR
     return S_OK;
 }
 
-static HRESULT Math_atan(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Math_atan(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     double x;
@@ -133,12 +133,12 @@ static HRESULT Math_atan(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPAR
 
     TRACE("\n");
 
-    if(!arg_cnt(dp)) {
+    if(!argc) {
         if(retv) num_set_val(retv, NAN);
         return S_OK;
     }
 
-    hres = to_number(ctx, get_arg(dp, 0), ei, &x);
+    hres = to_number(ctx, argv, ei, &x);
     if(FAILED(hres))
         return hres;
 
@@ -146,7 +146,7 @@ static HRESULT Math_atan(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPAR
     return S_OK;
 }
 
-static HRESULT Math_atan2(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Math_atan2(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     double x, y;
@@ -154,16 +154,16 @@ static HRESULT Math_atan2(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPA
 
     TRACE("\n");
 
-    if(arg_cnt(dp)<2) {
+    if(argc<2) {
         if(retv) num_set_val(retv, NAN);
         return S_OK;
     }
 
-    hres = to_number(ctx, get_arg(dp, 0), ei, &y);
+    hres = to_number(ctx, argv, ei, &y);
     if(FAILED(hres))
         return hres;
 
-    hres = to_number(ctx, get_arg(dp, 1), ei, &x);
+    hres = to_number(ctx, argv+1, ei, &x);
     if(FAILED(hres))
         return hres;
 
@@ -172,7 +172,7 @@ static HRESULT Math_atan2(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPA
 }
 
 /* ECMA-262 3rd Edition    15.8.2.6 */
-static HRESULT Math_ceil(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Math_ceil(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     double x;
@@ -180,13 +180,13 @@ static HRESULT Math_ceil(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPAR
 
     TRACE("\n");
 
-    if(!arg_cnt(dp)) {
+    if(!argc) {
         if(retv)
             num_set_val(retv, NAN);
         return S_OK;
     }
 
-    hres = to_number(ctx, get_arg(dp, 0), ei, &x);
+    hres = to_number(ctx, argv, ei, &x);
     if(FAILED(hres))
         return hres;
 
@@ -195,7 +195,7 @@ static HRESULT Math_ceil(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPAR
     return S_OK;
 }
 
-static HRESULT Math_cos(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Math_cos(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     double x;
@@ -203,12 +203,12 @@ static HRESULT Math_cos(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARA
 
     TRACE("\n");
 
-    if(!arg_cnt(dp)) {
+    if(!argc) {
         if(retv) num_set_val(retv, NAN);
         return S_OK;
     }
 
-    hres = to_number(ctx, get_arg(dp, 0), ei, &x);
+    hres = to_number(ctx, argv, ei, &x);
     if(FAILED(hres))
         return hres;
 
@@ -216,7 +216,7 @@ static HRESULT Math_cos(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARA
     return S_OK;
 }
 
-static HRESULT Math_exp(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Math_exp(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     double x;
@@ -224,12 +224,12 @@ static HRESULT Math_exp(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARA
 
     TRACE("\n");
 
-    if(!arg_cnt(dp)) {
+    if(!argc) {
         if(retv) num_set_val(retv, NAN);
         return S_OK;
     }
 
-    hres = to_number(ctx, get_arg(dp, 0), ei, &x);
+    hres = to_number(ctx, argv, ei, &x);
     if(FAILED(hres))
         return hres;
 
@@ -237,7 +237,7 @@ static HRESULT Math_exp(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARA
     return S_OK;
 }
 
-static HRESULT Math_floor(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Math_floor(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     double x;
@@ -245,13 +245,13 @@ static HRESULT Math_floor(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPA
 
     TRACE("\n");
 
-    if(!arg_cnt(dp)) {
+    if(!argc) {
         if(retv)
             num_set_val(retv, NAN);
         return S_OK;
     }
 
-    hres = to_number(ctx, get_arg(dp, 0), ei, &x);
+    hres = to_number(ctx, argv, ei, &x);
     if(FAILED(hres))
         return hres;
 
@@ -260,7 +260,7 @@ static HRESULT Math_floor(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPA
     return S_OK;
 }
 
-static HRESULT Math_log(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Math_log(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     double x;
@@ -268,13 +268,13 @@ static HRESULT Math_log(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARA
 
     TRACE("\n");
 
-    if(!arg_cnt(dp)) {
+    if(!argc) {
         if(retv)
             num_set_val(retv, NAN);
         return S_OK;
     }
 
-    hres = to_number(ctx, get_arg(dp, 0), ei, &x);
+    hres = to_number(ctx, argv, ei, &x);
     if(FAILED(hres))
         return hres;
 
@@ -284,7 +284,7 @@ static HRESULT Math_log(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARA
 }
 
 /* ECMA-262 3rd Edition    15.8.2.11 */
-static HRESULT Math_max(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Math_max(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     DOUBLE max, d;
@@ -293,18 +293,18 @@ static HRESULT Math_max(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARA
 
     TRACE("\n");
 
-    if(!arg_cnt(dp)) {
+    if(!argc) {
         if(retv)
             num_set_val(retv, -INFINITY);
         return S_OK;
     }
 
-    hres = to_number(ctx, get_arg(dp, 0), ei, &max);
+    hres = to_number(ctx, argv, ei, &max);
     if(FAILED(hres))
         return hres;
 
-    for(i=1; i < arg_cnt(dp); i++) {
-        hres = to_number(ctx, get_arg(dp, i), ei, &d);
+    for(i=1; i < argc; i++) {
+        hres = to_number(ctx, argv+i, ei, &d);
         if(FAILED(hres))
             return hres;
 
@@ -318,7 +318,7 @@ static HRESULT Math_max(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARA
 }
 
 /* ECMA-262 3rd Edition    15.8.2.12 */
-static HRESULT Math_min(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Math_min(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     DOUBLE min, d;
@@ -327,18 +327,18 @@ static HRESULT Math_min(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARA
 
     TRACE("\n");
 
-    if(!arg_cnt(dp)) {
+    if(!argc) {
         if(retv)
             num_set_val(retv, INFINITY);
         return S_OK;
     }
 
-    hres = to_number(ctx, get_arg(dp, 0), ei, &min);
+    hres = to_number(ctx, argv, ei, &min);
     if(FAILED(hres))
         return hres;
 
-    for(i=1; i < arg_cnt(dp); i++) {
-        hres = to_number(ctx, get_arg(dp, i), ei, &d);
+    for(i=1; i < argc; i++) {
+        hres = to_number(ctx, argv+i, ei, &d);
         if(FAILED(hres))
             return hres;
 
@@ -352,7 +352,7 @@ static HRESULT Math_min(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARA
 }
 
 /* ECMA-262 3rd Edition    15.8.2.13 */
-static HRESULT Math_pow(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Math_pow(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     double x, y;
@@ -360,16 +360,16 @@ static HRESULT Math_pow(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARA
 
     TRACE("\n");
 
-    if(arg_cnt(dp) < 2) {
+    if(argc < 2) {
         if(retv) num_set_val(retv, NAN);
         return S_OK;
     }
 
-    hres = to_number(ctx, get_arg(dp, 0), ei, &x);
+    hres = to_number(ctx, argv, ei, &x);
     if(FAILED(hres))
         return hres;
 
-    hres = to_number(ctx, get_arg(dp, 1), ei, &y);
+    hres = to_number(ctx, argv+1, ei, &y);
     if(FAILED(hres))
         return hres;
 
@@ -379,7 +379,7 @@ static HRESULT Math_pow(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARA
 }
 
 /* ECMA-262 3rd Edition    15.8.2.14 */
-static HRESULT Math_random(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Math_random(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     UINT r;
@@ -396,7 +396,7 @@ static HRESULT Math_random(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPP
 }
 
 /* ECMA-262 3rd Edition    15.8.2.15 */
-static HRESULT Math_round(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Math_round(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     double x;
@@ -404,13 +404,13 @@ static HRESULT Math_round(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPA
 
     TRACE("\n");
 
-    if(!arg_cnt(dp)) {
+    if(!argc) {
         if(retv)
             num_set_val(retv, NAN);
         return S_OK;
     }
 
-    hres = to_number(ctx, get_arg(dp, 0), ei, &x);
+    hres = to_number(ctx, argv, ei, &x);
     if(FAILED(hres))
         return hres;
 
@@ -419,7 +419,7 @@ static HRESULT Math_round(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPA
     return S_OK;
 }
 
-static HRESULT Math_sin(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Math_sin(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     double x;
@@ -427,12 +427,12 @@ static HRESULT Math_sin(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARA
 
     TRACE("\n");
 
-    if(!arg_cnt(dp)) {
+    if(!argc) {
         if(retv) num_set_val(retv, NAN);
         return S_OK;
     }
 
-    hres = to_number(ctx, get_arg(dp, 0), ei, &x);
+    hres = to_number(ctx, argv, ei, &x);
     if(FAILED(hres))
         return hres;
 
@@ -440,7 +440,7 @@ static HRESULT Math_sin(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARA
     return S_OK;
 }
 
-static HRESULT Math_sqrt(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Math_sqrt(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     double x;
@@ -448,12 +448,12 @@ static HRESULT Math_sqrt(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPAR
 
     TRACE("\n");
 
-    if(!arg_cnt(dp)) {
+    if(!argc) {
         if(retv) num_set_val(retv, NAN);
         return S_OK;
     }
 
-    hres = to_number(ctx, get_arg(dp, 0), ei, &x);
+    hres = to_number(ctx, argv, ei, &x);
     if(FAILED(hres))
         return hres;
 
@@ -461,7 +461,7 @@ static HRESULT Math_sqrt(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPAR
     return S_OK;
 }
 
-static HRESULT Math_tan(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Math_tan(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     double x;
@@ -469,12 +469,12 @@ static HRESULT Math_tan(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARA
 
     TRACE("\n");
 
-    if(!arg_cnt(dp)) {
+    if(!argc) {
         if(retv) num_set_val(retv, NAN);
         return S_OK;
     }
 
-    hres = to_number(ctx, get_arg(dp, 0), ei, &x);
+    hres = to_number(ctx, argv, ei, &x);
     if(FAILED(hres))
         return hres;
 
diff --git a/dlls/jscript/number.c b/dlls/jscript/number.c
index 3d2283aec34..c62d985f4da 100644
--- a/dlls/jscript/number.c
+++ b/dlls/jscript/number.c
@@ -218,7 +218,7 @@ static inline void number_to_exponential(double val, int prec, BSTR *out)
 }
 
 /* ECMA-262 3rd Edition    15.7.4.2 */
-static HRESULT Number_toString(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Number_toString(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     NumberInstance *number;
@@ -232,8 +232,8 @@ static HRESULT Number_toString(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, D
     if(!(number = number_this(jsthis)))
         return throw_type_error(ctx, ei, JS_E_NUMBER_EXPECTED, NULL);
 
-    if(arg_cnt(dp)) {
-        hres = to_int32(ctx, get_arg(dp, 0), ei, &radix);
+    if(argc) {
+        hres = to_int32(ctx, argv, ei, &radix);
         if(FAILED(hres))
             return hres;
 
@@ -343,14 +343,14 @@ static HRESULT Number_toString(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, D
     return S_OK;
 }
 
-static HRESULT Number_toLocaleString(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Number_toLocaleString(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     FIXME("\n");
     return E_NOTIMPL;
 }
 
-static HRESULT Number_toFixed(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Number_toFixed(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     NumberInstance *number;
@@ -364,8 +364,8 @@ static HRESULT Number_toFixed(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DI
     if(!(number = number_this(jsthis)))
         return throw_type_error(ctx, ei, JS_E_NUMBER_EXPECTED, NULL);
 
-    if(arg_cnt(dp)) {
-        hres = to_int32(ctx, get_arg(dp, 0), ei, &prec);
+    if(argc) {
+        hres = to_int32(ctx, argv, ei, &prec);
         if(FAILED(hres))
             return hres;
 
@@ -394,7 +394,7 @@ static HRESULT Number_toFixed(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DI
     return S_OK;
 }
 
-static HRESULT Number_toExponential(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Number_toExponential(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     NumberInstance *number;
@@ -408,8 +408,8 @@ static HRESULT Number_toExponential(script_ctx_t *ctx, vdisp_t *jsthis, WORD fla
     if(!(number = number_this(jsthis)))
         return throw_type_error(ctx, ei, JS_E_NUMBER_EXPECTED, NULL);
 
-    if(arg_cnt(dp)) {
-        hres = to_int32(ctx, get_arg(dp, 0), ei, &prec);
+    if(argc) {
+        hres = to_int32(ctx, argv, ei, &prec);
         if(FAILED(hres))
             return hres;
 
@@ -440,7 +440,7 @@ static HRESULT Number_toExponential(script_ctx_t *ctx, vdisp_t *jsthis, WORD fla
     return S_OK;
 }
 
-static HRESULT Number_toPrecision(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Number_toPrecision(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     NumberInstance *number;
@@ -452,8 +452,8 @@ static HRESULT Number_toPrecision(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags
     if(!(number = number_this(jsthis)))
         return throw_type_error(ctx, ei, JS_E_NUMBER_EXPECTED, NULL);
 
-    if(arg_cnt(dp)) {
-        hres = to_int32(ctx, get_arg(dp, 0), ei, &prec);
+    if(argc) {
+        hres = to_int32(ctx, argv, ei, &prec);
         if(FAILED(hres))
             return hres;
 
@@ -490,7 +490,7 @@ static HRESULT Number_toPrecision(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags
     return S_OK;
 }
 
-static HRESULT Number_valueOf(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Number_valueOf(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     NumberInstance *number;
@@ -505,7 +505,7 @@ static HRESULT Number_valueOf(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DI
     return S_OK;
 }
 
-static HRESULT Number_value(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Number_value(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     NumberInstance *number = number_from_vdisp(jsthis);
@@ -543,7 +543,7 @@ static const builtin_info_t Number_info = {
     NULL
 };
 
-static HRESULT NumberConstr_value(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT NumberConstr_value(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     double n;
@@ -553,13 +553,13 @@ static HRESULT NumberConstr_value(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags
 
     switch(flags) {
     case INVOKE_FUNC:
-        if(!arg_cnt(dp)) {
+        if(!argc) {
             if(retv)
                 num_set_int(retv, 0);
             return S_OK;
         }
 
-        hres = to_number(ctx, get_arg(dp, 0), ei, &n);
+        hres = to_number(ctx, argv, ei, &n);
         if(FAILED(hres))
             return hres;
 
@@ -570,8 +570,8 @@ static HRESULT NumberConstr_value(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags
     case DISPATCH_CONSTRUCT: {
         jsdisp_t *obj;
 
-        if(arg_cnt(dp)) {
-            hres = to_number(ctx, get_arg(dp, 0), ei, &n);
+        if(argc) {
+            hres = to_number(ctx, argv, ei, &n);
             if(FAILED(hres))
                 return hres;
         }else {
diff --git a/dlls/jscript/object.c b/dlls/jscript/object.c
index a1afac2f965..b1a83de86fd 100644
--- a/dlls/jscript/object.c
+++ b/dlls/jscript/object.c
@@ -32,7 +32,7 @@ static const WCHAR isPrototypeOfW[] = {'i','s','P','r','o','t','o','t','y','p','
 
 static const WCHAR default_valueW[] = {'[','o','b','j','e','c','t',' ','O','b','j','e','c','t',']',0};
 
-static HRESULT Object_toString(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Object_toString(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     jsdisp_t *jsdisp;
@@ -78,11 +78,9 @@ static HRESULT Object_toString(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, D
     return S_OK;
 }
 
-static HRESULT Object_toLocaleString(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Object_toLocaleString(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
-    DISPPARAMS params = {NULL, NULL, 0, 0};
-
     TRACE("\n");
 
     if(!is_jsdisp(jsthis)) {
@@ -90,10 +88,10 @@ static HRESULT Object_toLocaleString(script_ctx_t *ctx, vdisp_t *jsthis, WORD fl
         return E_FAIL;
     }
 
-    return jsdisp_call_name(jsthis->u.jsdisp, toStringW, DISPATCH_METHOD, &params, retv, ei);
+    return jsdisp_call_name(jsthis->u.jsdisp, toStringW, DISPATCH_METHOD, 0, NULL, retv, ei);
 }
 
-static HRESULT Object_valueOf(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Object_valueOf(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     TRACE("\n");
@@ -108,7 +106,7 @@ static HRESULT Object_valueOf(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DI
     return S_OK;
 }
 
-static HRESULT Object_hasOwnProperty(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Object_hasOwnProperty(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     BSTR name;
@@ -118,7 +116,7 @@ static HRESULT Object_hasOwnProperty(script_ctx_t *ctx, vdisp_t *jsthis, WORD fl
 
     TRACE("\n");
 
-    if(!arg_cnt(dp)) {
+    if(!argc) {
         if(retv) {
             V_VT(retv) = VT_BOOL;
             V_BOOL(retv) = VARIANT_FALSE;
@@ -127,7 +125,7 @@ static HRESULT Object_hasOwnProperty(script_ctx_t *ctx, vdisp_t *jsthis, WORD fl
         return S_OK;
     }
 
-    hres = to_string(ctx, get_arg(dp, 0), ei, &name);
+    hres = to_string(ctx, argv, ei, &name);
     if(FAILED(hres))
         return hres;
 
@@ -154,21 +152,21 @@ static HRESULT Object_hasOwnProperty(script_ctx_t *ctx, vdisp_t *jsthis, WORD fl
     return S_OK;
 }
 
-static HRESULT Object_propertyIsEnumerable(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Object_propertyIsEnumerable(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     FIXME("\n");
     return E_NOTIMPL;
 }
 
-static HRESULT Object_isPrototypeOf(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Object_isPrototypeOf(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     FIXME("\n");
     return E_NOTIMPL;
 }
 
-static HRESULT Object_value(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT Object_value(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     TRACE("\n");
@@ -213,7 +211,7 @@ static const builtin_info_t Object_info = {
     NULL
 };
 
-static HRESULT ObjectConstr_value(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT ObjectConstr_value(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     HRESULT hres;
@@ -222,13 +220,11 @@ static HRESULT ObjectConstr_value(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags
 
     switch(flags) {
     case DISPATCH_METHOD:
-        if(arg_cnt(dp)) {
-            VARIANT *arg = get_arg(dp,0);
-
-            if(V_VT(arg) != VT_EMPTY && V_VT(arg) != VT_NULL && (V_VT(arg) != VT_DISPATCH || V_DISPATCH(arg))) {
+        if(argc) {
+            if(V_VT(argv) != VT_EMPTY && V_VT(argv) != VT_NULL && (V_VT(argv) != VT_DISPATCH || V_DISPATCH(argv))) {
                 IDispatch *disp;
 
-                hres = to_object(ctx, arg, &disp);
+                hres = to_object(ctx, argv, &disp);
                 if(FAILED(hres))
                     return hres;
 
diff --git a/dlls/jscript/regexp.c b/dlls/jscript/regexp.c
index 399635ec8c2..8e5445f2671 100644
--- a/dlls/jscript/regexp.c
+++ b/dlls/jscript/regexp.c
@@ -3473,7 +3473,7 @@ HRESULT regexp_match(script_ctx_t *ctx, jsdisp_t *dispex, const WCHAR *str, DWOR
     return S_OK;
 }
 
-static HRESULT RegExp_source(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT RegExp_source(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     TRACE("\n");
@@ -3496,21 +3496,21 @@ static HRESULT RegExp_source(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DIS
     return S_OK;
 }
 
-static HRESULT RegExp_global(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT RegExp_global(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     FIXME("\n");
     return E_NOTIMPL;
 }
 
-static HRESULT RegExp_ignoreCase(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT RegExp_ignoreCase(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     FIXME("\n");
     return E_NOTIMPL;
 }
 
-static HRESULT RegExp_multiline(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT RegExp_multiline(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     FIXME("\n");
@@ -3534,7 +3534,7 @@ static INT index_from_var(script_ctx_t *ctx, VARIANT *v)
     return is_int32(n) ? n : 0;
 }
 
-static HRESULT RegExp_lastIndex(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT RegExp_lastIndex(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     TRACE("\n");
@@ -3548,15 +3548,13 @@ static HRESULT RegExp_lastIndex(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags,
     }
     case DISPATCH_PROPERTYPUT: {
         RegExpInstance *regexp = regexp_from_vdisp(jsthis);
-        VARIANT *arg;
         HRESULT hres;
 
-        arg = get_arg(dp,0);
-        hres = VariantCopy(&regexp->last_index_var, arg);
+        hres = VariantCopy(&regexp->last_index_var, argv);
         if(FAILED(hres))
             return hres;
 
-        regexp->last_index = index_from_var(ctx, arg);
+        regexp->last_index = index_from_var(ctx, argv);
         break;
     }
     default:
@@ -3567,7 +3565,7 @@ static HRESULT RegExp_lastIndex(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags,
     return S_OK;
 }
 
-static HRESULT RegExp_toString(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT RegExp_toString(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     FIXME("\n");
@@ -3698,7 +3696,7 @@ static HRESULT run_exec(script_ctx_t *ctx, vdisp_t *jsthis, VARIANT *arg, jsexce
     return S_OK;
 }
 
-static HRESULT RegExp_exec(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT RegExp_exec(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     match_result_t *parens = NULL, match;
@@ -3709,7 +3707,7 @@ static HRESULT RegExp_exec(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPP
 
     TRACE("\n");
 
-    hres = run_exec(ctx, jsthis, arg_cnt(dp) ? get_arg(dp,0) : NULL, ei, &string, &match, &parens, &parens_cnt, &b);
+    hres = run_exec(ctx, jsthis, argc ? argv : NULL, ei, &string, &match, &parens, &parens_cnt, &b);
     if(FAILED(hres))
         return hres;
 
@@ -3732,18 +3730,16 @@ static HRESULT RegExp_exec(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPP
     return hres;
 }
 
-static HRESULT RegExp_test(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT RegExp_test(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     match_result_t match;
     VARIANT undef_var;
     VARIANT_BOOL b;
-    DWORD argc;
     HRESULT hres;
 
     TRACE("\n");
 
-    argc = arg_cnt(dp);
     if(!argc) {
         V_VT(&undef_var) = VT_BSTR;
         V_BSTR(&undef_var) = SysAllocString(undefinedW);
@@ -3751,7 +3747,7 @@ static HRESULT RegExp_test(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPP
             return E_OUTOFMEMORY;
     }
 
-    hres = run_exec(ctx, jsthis, argc ? get_arg(dp,0) : &undef_var, ei, NULL, &match, NULL, NULL, &b);
+    hres = run_exec(ctx, jsthis, argc ? argv : &undef_var, ei, NULL, &match, NULL, NULL, &b);
     if(!argc)
         SysFreeString(V_BSTR(&undef_var));
     if(FAILED(hres))
@@ -3764,7 +3760,7 @@ static HRESULT RegExp_test(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPP
     return S_OK;
 }
 
-static HRESULT RegExp_value(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT RegExp_value(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     TRACE("\n");
@@ -4014,7 +4010,7 @@ HRESULT regexp_string_match(script_ctx_t *ctx, jsdisp_t *re, BSTR str,
 }
 
 static HRESULT RegExpConstr_leftContext(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags,
-         DISPPARAMS *dp, VARIANT *retv, jsexcept_t *ei)
+         unsigned argc, VARIANT *argv, VARIANT *retv, jsexcept_t *ei)
 {
     TRACE("\n");
 
@@ -4041,7 +4037,7 @@ static HRESULT RegExpConstr_leftContext(script_ctx_t *ctx, vdisp_t *jsthis, WORD
 }
 
 static HRESULT RegExpConstr_rightContext(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags,
-         DISPPARAMS *dp, VARIANT *retv, jsexcept_t *ei)
+         unsigned argc, VARIANT *argv, VARIANT *retv, jsexcept_t *ei)
 {
     TRACE("\n");
 
@@ -4067,20 +4063,19 @@ static HRESULT RegExpConstr_rightContext(script_ctx_t *ctx, vdisp_t *jsthis, WOR
     return S_OK;
 }
 
-static HRESULT RegExpConstr_value(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT RegExpConstr_value(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     TRACE("\n");
 
     switch(flags) {
     case DISPATCH_METHOD:
-        if(arg_cnt(dp)) {
-            VARIANT *arg = get_arg(dp,0);
-            if(V_VT(arg) == VT_DISPATCH) {
-                jsdisp_t *jsdisp = iface_to_jsdisp((IUnknown*)V_DISPATCH(arg));
+        if(argc) {
+            if(V_VT(argv) == VT_DISPATCH) {
+                jsdisp_t *jsdisp = iface_to_jsdisp((IUnknown*)V_DISPATCH(argv));
                 if(jsdisp) {
                     if(is_class(jsdisp, JSCLASS_REGEXP)) {
-                        if(arg_cnt(dp) > 1 && V_VT(get_arg(dp,1)) != VT_EMPTY) {
+                        if(argc > 1 && V_VT(argv+1) != VT_EMPTY) {
                             jsdisp_release(jsdisp);
                             return throw_regexp_error(ctx, ei, JS_E_REGEXP_SYNTAX, NULL);
                         }
@@ -4100,12 +4095,12 @@ static HRESULT RegExpConstr_value(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags
         jsdisp_t *ret;
         HRESULT hres;
 
-        if(!arg_cnt(dp)) {
+        if(!argc) {
             FIXME("no args\n");
             return E_NOTIMPL;
         }
 
-        hres = create_regexp_var(ctx, get_arg(dp,0), arg_cnt(dp) > 1 ? get_arg(dp,1) : NULL, &ret);
+        hres = create_regexp_var(ctx, argv, argc > 1 ? argv+1 : NULL, &ret);
         if(FAILED(hres))
             return hres;
 
diff --git a/dlls/jscript/string.c b/dlls/jscript/string.c
index 1cc20488d9e..46d779a93aa 100644
--- a/dlls/jscript/string.c
+++ b/dlls/jscript/string.c
@@ -102,7 +102,7 @@ static HRESULT get_string_val(script_ctx_t *ctx, vdisp_t *jsthis, jsexcept_t *ei
     return S_OK;
 }
 
-static HRESULT String_length(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT String_length(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     TRACE("%p\n", jsthis);
@@ -143,7 +143,7 @@ static HRESULT stringobj_to_string(vdisp_t *jsthis, VARIANT *retv)
 }
 
 /* ECMA-262 3rd Edition    15.5.4.2 */
-static HRESULT String_toString(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT String_toString(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     TRACE("\n");
@@ -152,7 +152,7 @@ static HRESULT String_toString(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, D
 }
 
 /* ECMA-262 3rd Edition    15.5.4.2 */
-static HRESULT String_valueOf(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT String_valueOf(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     TRACE("\n");
@@ -191,7 +191,7 @@ static HRESULT do_attributeless_tag_format(script_ctx_t *ctx, vdisp_t *jsthis, V
     return S_OK;
 }
 
-static HRESULT do_attribute_tag_format(script_ctx_t *ctx, vdisp_t *jsthis, DISPPARAMS *dp, VARIANT *retv,
+static HRESULT do_attribute_tag_format(script_ctx_t *ctx, vdisp_t *jsthis, unsigned argc, VARIANT *argv, VARIANT *retv,
         jsexcept_t *ei, const WCHAR *tagname, const WCHAR *attr)
 {
     static const WCHAR tagfmtW[]
@@ -222,8 +222,8 @@ static HRESULT do_attribute_tag_format(script_ctx_t *ctx, vdisp_t *jsthis, DISPP
         length = string->length;
     }
 
-    if(arg_cnt(dp)) {
-        hres = to_string(ctx, get_arg(dp, 0), ei, &attr_value);
+    if(argc) {
+        hres = to_string(ctx, argv, ei, &attr_value);
         if(FAILED(hres)) {
             SysFreeString(val_str);
             return hres;
@@ -257,30 +257,30 @@ static HRESULT do_attribute_tag_format(script_ctx_t *ctx, vdisp_t *jsthis, DISPP
     return S_OK;
 }
 
-static HRESULT String_anchor(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT String_anchor(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     static const WCHAR fontW[] = {'A',0};
     static const WCHAR colorW[] = {'N','A','M','E',0};
 
-    return do_attribute_tag_format(ctx, jsthis, dp, retv, ei, fontW, colorW);
+    return do_attribute_tag_format(ctx, jsthis, argc, argv, retv, ei, fontW, colorW);
 }
 
-static HRESULT String_big(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT String_big(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     static const WCHAR bigtagW[] = {'B','I','G',0};
     return do_attributeless_tag_format(ctx, jsthis, retv, ei, bigtagW);
 }
 
-static HRESULT String_blink(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT String_blink(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     static const WCHAR blinktagW[] = {'B','L','I','N','K',0};
     return do_attributeless_tag_format(ctx, jsthis, retv, ei, blinktagW);
 }
 
-static HRESULT String_bold(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT String_bold(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     static const WCHAR boldtagW[] = {'B',0};
@@ -288,7 +288,7 @@ static HRESULT String_bold(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPP
 }
 
 /* ECMA-262 3rd Edition    15.5.4.5 */
-static HRESULT String_charAt(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT String_charAt(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     const WCHAR *str;
@@ -303,10 +303,10 @@ static HRESULT String_charAt(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DIS
     if(FAILED(hres))
         return hres;
 
-    if(arg_cnt(dp)) {
+    if(argc) {
         double d;
 
-        hres = to_integer(ctx, get_arg(dp, 0), ei, &d);
+        hres = to_integer(ctx, argv, ei, &d);
         if(FAILED(hres)) {
             SysFreeString(val_str);
             return hres;
@@ -334,7 +334,7 @@ static HRESULT String_charAt(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DIS
 }
 
 /* ECMA-262 3rd Edition    15.5.4.5 */
-static HRESULT String_charCodeAt(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT String_charCodeAt(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     const WCHAR *str;
@@ -348,10 +348,10 @@ static HRESULT String_charCodeAt(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags,
     if(FAILED(hres))
         return hres;
 
-    if(arg_cnt(dp) > 0) {
+    if(argc > 0) {
         double d;
 
-        hres = to_integer(ctx, get_arg(dp, 0), ei, &d);
+        hres = to_integer(ctx, argv, ei, &d);
         if(FAILED(hres)) {
             SysFreeString(val_str);
             return hres;
@@ -375,7 +375,7 @@ static HRESULT String_charCodeAt(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags,
 }
 
 /* ECMA-262 3rd Edition    15.5.4.6 */
-static HRESULT String_concat(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT String_concat(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     BSTR *strs = NULL, ret = NULL;
@@ -386,7 +386,7 @@ static HRESULT String_concat(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DIS
 
     TRACE("\n");
 
-    str_cnt = arg_cnt(dp)+1;
+    str_cnt = argc+1;
     strs = heap_alloc_zero(str_cnt * sizeof(BSTR));
     if(!strs)
         return E_OUTOFMEMORY;
@@ -396,8 +396,8 @@ static HRESULT String_concat(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DIS
 
     hres = to_string(ctx, &var, ei, strs);
     if(SUCCEEDED(hres)) {
-        for(i=0; i < arg_cnt(dp); i++) {
-            hres = to_string(ctx, get_arg(dp, i), ei, strs+i+1);
+        for(i=0; i < argc; i++) {
+            hres = to_string(ctx, argv+i, ei, strs+i+1);
             if(FAILED(hres))
                 break;
         }
@@ -432,32 +432,32 @@ static HRESULT String_concat(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DIS
     return S_OK;
 }
 
-static HRESULT String_fixed(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT String_fixed(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     static const WCHAR fixedtagW[] = {'T','T',0};
     return do_attributeless_tag_format(ctx, jsthis, retv, ei, fixedtagW);
 }
 
-static HRESULT String_fontcolor(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT String_fontcolor(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     static const WCHAR fontW[] = {'F','O','N','T',0};
     static const WCHAR colorW[] = {'C','O','L','O','R',0};
 
-    return do_attribute_tag_format(ctx, jsthis, dp, retv, ei, fontW, colorW);
+    return do_attribute_tag_format(ctx, jsthis, argc, argv, retv, ei, fontW, colorW);
 }
 
-static HRESULT String_fontsize(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT String_fontsize(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     static const WCHAR fontW[] = {'F','O','N','T',0};
     static const WCHAR colorW[] = {'S','I','Z','E',0};
 
-    return do_attribute_tag_format(ctx, jsthis, dp, retv, ei, fontW, colorW);
+    return do_attribute_tag_format(ctx, jsthis, argc, argv, retv, ei, fontW, colorW);
 }
 
-static HRESULT String_indexOf(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT String_indexOf(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     DWORD length, pos = 0;
@@ -472,23 +472,23 @@ static HRESULT String_indexOf(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DI
     if(FAILED(hres))
         return hres;
 
-    if(!arg_cnt(dp)) {
+    if(!argc) {
         if(retv)
             num_set_int(retv, -1);
         SysFreeString(val_str);
         return S_OK;
     }
 
-    hres = to_string(ctx, get_arg(dp,0), ei, &search_str);
+    hres = to_string(ctx, argv, ei, &search_str);
     if(FAILED(hres)) {
         SysFreeString(val_str);
         return hres;
     }
 
-    if(arg_cnt(dp) >= 2) {
+    if(argc >= 2) {
         double d;
 
-        hres = to_integer(ctx, get_arg(dp,1), ei, &d);
+        hres = to_integer(ctx, argv+1, ei, &d);
         if(SUCCEEDED(hres) && d > 0.0)
             pos = is_int32(d) ? min(length, d) : length;
     }
@@ -513,7 +513,7 @@ static HRESULT String_indexOf(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DI
     return S_OK;
 }
 
-static HRESULT String_italics(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT String_italics(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     static const WCHAR italicstagW[] = {'I',0};
@@ -521,7 +521,7 @@ static HRESULT String_italics(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DI
 }
 
 /* ECMA-262 3rd Edition    15.5.4.8 */
-static HRESULT String_lastIndexOf(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT String_lastIndexOf(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     BSTR search_str, val_str;
@@ -536,14 +536,14 @@ static HRESULT String_lastIndexOf(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags
     if(FAILED(hres))
         return hres;
 
-    if(!arg_cnt(dp)) {
+    if(!argc) {
         if(retv)
             num_set_int(retv, -1);
         SysFreeString(val_str);
         return S_OK;
     }
 
-    hres = to_string(ctx, get_arg(dp,0), ei, &search_str);
+    hres = to_string(ctx, argv, ei, &search_str);
     if(FAILED(hres)) {
         SysFreeString(val_str);
         return hres;
@@ -551,10 +551,10 @@ static HRESULT String_lastIndexOf(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags
 
     search_len = SysStringLen(search_str);
 
-    if(arg_cnt(dp) >= 2) {
+    if(argc >= 2) {
         double d;
 
-        hres = to_integer(ctx, get_arg(dp,1), ei, &d);
+        hres = to_integer(ctx, argv+1, ei, &d);
         if(SUCCEEDED(hres) && d > 0)
             pos = is_int32(d) ? min(length, d) : length;
     }else {
@@ -582,29 +582,28 @@ static HRESULT String_lastIndexOf(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags
     return S_OK;
 }
 
-static HRESULT String_link(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT String_link(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     static const WCHAR fontW[] = {'A',0};
     static const WCHAR colorW[] = {'H','R','E','F',0};
 
-    return do_attribute_tag_format(ctx, jsthis, dp, retv, ei, fontW, colorW);
+    return do_attribute_tag_format(ctx, jsthis, argc, argv, retv, ei, fontW, colorW);
 }
 
 /* ECMA-262 3rd Edition    15.5.4.10 */
-static HRESULT String_match(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT String_match(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     const WCHAR *str;
     jsdisp_t *regexp;
-    VARIANT *arg_var;
     DWORD length;
     BSTR val_str = NULL;
     HRESULT hres = S_OK;
 
     TRACE("\n");
 
-    if(!arg_cnt(dp)) {
+    if(!argc) {
         if(retv) {
             V_VT(retv) = VT_NULL;
         }
@@ -612,10 +611,9 @@ static HRESULT String_match(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISP
         return S_OK;
     }
 
-    arg_var = get_arg(dp, 0);
-    switch(V_VT(arg_var)) {
+    switch(V_VT(argv)) {
     case VT_DISPATCH:
-        regexp = iface_to_jsdisp((IUnknown*)V_DISPATCH(arg_var));
+        regexp = iface_to_jsdisp((IUnknown*)V_DISPATCH(argv));
         if(regexp) {
             if(is_class(regexp, JSCLASS_REGEXP))
                 break;
@@ -624,7 +622,7 @@ static HRESULT String_match(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISP
     default: {
         BSTR match_str;
 
-        hres = to_string(ctx, arg_var, ei, &match_str);
+        hres = to_string(ctx, argv, ei, &match_str);
         if(FAILED(hres))
             return hres;
 
@@ -687,29 +685,27 @@ static HRESULT strbuf_append(strbuf_t *buf, const WCHAR *str, DWORD len)
 static HRESULT rep_call(script_ctx_t *ctx, jsdisp_t *func, const WCHAR *str, match_result_t *match,
         match_result_t *parens, DWORD parens_cnt, BSTR *ret, jsexcept_t *ei)
 {
-    DISPPARAMS dp = {NULL, NULL, 0, 0};
-    VARIANTARG *args, *arg;
+    VARIANT *argv;
+    unsigned argc;
     VARIANT var;
     DWORD i;
     HRESULT hres = S_OK;
 
-    dp.cArgs = parens_cnt+3;
-    dp.rgvarg = args = heap_alloc_zero(sizeof(VARIANT)*dp.cArgs);
-    if(!args)
+    argc = parens_cnt+3;
+    argv = heap_alloc_zero(sizeof(VARIANT)*argc);
+    if(!argv)
         return E_OUTOFMEMORY;
 
-    arg = get_arg(&dp,0);
-    V_VT(arg) = VT_BSTR;
-    V_BSTR(arg) = SysAllocStringLen(match->str, match->len);
-    if(!V_BSTR(arg))
+    V_VT(argv) = VT_BSTR;
+    V_BSTR(argv) = SysAllocStringLen(match->str, match->len);
+    if(!V_BSTR(argv))
         hres = E_OUTOFMEMORY;
 
     if(SUCCEEDED(hres)) {
         for(i=0; i < parens_cnt; i++) {
-            arg = get_arg(&dp,i+1);
-            V_VT(arg) = VT_BSTR;
-            V_BSTR(arg) = SysAllocStringLen(parens[i].str, parens[i].len);
-            if(!V_BSTR(arg)) {
+            V_VT(argv+i+1) = VT_BSTR;
+            V_BSTR(argv+i+1) = SysAllocStringLen(parens[i].str, parens[i].len);
+            if(!V_BSTR(argv+i+1)) {
                hres = E_OUTOFMEMORY;
                break;
             }
@@ -717,24 +713,22 @@ static HRESULT rep_call(script_ctx_t *ctx, jsdisp_t *func, const WCHAR *str, mat
     }
 
     if(SUCCEEDED(hres)) {
-        arg = get_arg(&dp,parens_cnt+1);
-        num_set_int(arg, match->str - str);
+        num_set_int(argv+parens_cnt+1, match->str - str);
 
-        arg = get_arg(&dp,parens_cnt+2);
-        V_VT(arg) = VT_BSTR;
-        V_BSTR(arg) = SysAllocString(str);
-        if(!V_BSTR(arg))
+        V_VT(argv+parens_cnt+2) = VT_BSTR;
+        V_BSTR(argv+parens_cnt+2) = SysAllocString(str);
+        if(!V_BSTR(argv+parens_cnt+2))
             hres = E_OUTOFMEMORY;
     }
 
     if(SUCCEEDED(hres))
-        hres = jsdisp_call_value(func, NULL, DISPATCH_METHOD, &dp, &var, ei);
+        hres = jsdisp_call_value(func, NULL, DISPATCH_METHOD, argc, argv, &var, ei);
 
     for(i=0; i < parens_cnt+3; i++) {
         if(i != parens_cnt+1)
-            SysFreeString(V_BSTR(get_arg(&dp,i)));
+            SysFreeString(V_BSTR(argv+i));
     }
-    heap_free(args);
+    heap_free(argv);
 
     if(FAILED(hres))
         return hres;
@@ -745,7 +739,7 @@ static HRESULT rep_call(script_ctx_t *ctx, jsdisp_t *func, const WCHAR *str, mat
 }
 
 /* ECMA-262 3rd Edition    15.5.4.11 */
-static HRESULT String_replace(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT String_replace(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     const WCHAR *str;
@@ -755,7 +749,6 @@ static HRESULT String_replace(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DI
     match_result_t *parens = NULL, match = {NULL,0}, **parens_ptr = &parens;
     strbuf_t ret = {NULL,0,0};
     DWORD re_flags = REM_NO_CTX_UPDATE;
-    VARIANT *arg_var;
     HRESULT hres = S_OK;
 
     TRACE("\n");
@@ -764,7 +757,7 @@ static HRESULT String_replace(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DI
     if(FAILED(hres))
         return hres;
 
-    if(!arg_cnt(dp)) {
+    if(!argc) {
         if(retv) {
             if(!val_str) {
                 val_str = SysAllocStringLen(str, length);
@@ -778,10 +771,9 @@ static HRESULT String_replace(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DI
         return S_OK;
     }
 
-    arg_var = get_arg(dp, 0);
-    switch(V_VT(arg_var)) {
+    switch(V_VT(argv)) {
     case VT_DISPATCH:
-        regexp = iface_to_jsdisp((IUnknown*)V_DISPATCH(arg_var));
+        regexp = iface_to_jsdisp((IUnknown*)V_DISPATCH(argv));
         if(regexp) {
             if(is_class(regexp, JSCLASS_REGEXP)) {
                 break;
@@ -792,18 +784,17 @@ static HRESULT String_replace(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DI
         }
 
     default:
-        hres = to_string(ctx, arg_var, ei, &match_str);
+        hres = to_string(ctx, argv, ei, &match_str);
         if(FAILED(hres)) {
             SysFreeString(val_str);
             return hres;
         }
     }
 
-    if(arg_cnt(dp) >= 2) {
-        arg_var = get_arg(dp,1);
-        switch(V_VT(arg_var)) {
+    if(argc >= 2) {
+        switch(V_VT(argv+1)) {
         case VT_DISPATCH:
-            rep_func = iface_to_jsdisp((IUnknown*)V_DISPATCH(arg_var));
+            rep_func = iface_to_jsdisp((IUnknown*)V_DISPATCH(argv+1));
             if(rep_func) {
                 if(is_class(rep_func, JSCLASS_FUNCTION)) {
                     break;
@@ -814,7 +805,7 @@ static HRESULT String_replace(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DI
             }
 
         default:
-            hres = to_string(ctx, arg_var, ei, &rep_str);
+            hres = to_string(ctx, argv+1, ei, &rep_str);
             if(FAILED(hres))
                 break;
 
@@ -984,13 +975,12 @@ static HRESULT String_replace(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DI
     return hres;
 }
 
-static HRESULT String_search(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT String_search(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     jsdisp_t *regexp = NULL;
     const WCHAR *str, *cp;
     match_result_t match;
-    VARIANT *arg;
     DWORD length;
     BSTR val_str;
     HRESULT hres;
@@ -1001,16 +991,15 @@ static HRESULT String_search(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DIS
     if(FAILED(hres))
         return hres;
 
-    if(!arg_cnt(dp)) {
+    if(!argc) {
         if(retv)
             V_VT(retv) = VT_NULL;
         SysFreeString(val_str);
         return S_OK;
     }
 
-    arg = get_arg(dp,0);
-    if(V_VT(arg) == VT_DISPATCH) {
-        regexp = iface_to_jsdisp((IUnknown*)V_DISPATCH(arg));
+    if(V_VT(argv) == VT_DISPATCH) {
+        regexp = iface_to_jsdisp((IUnknown*)V_DISPATCH(argv));
         if(regexp) {
             if(!is_class(regexp, JSCLASS_REGEXP)) {
                 jsdisp_release(regexp);
@@ -1020,7 +1009,7 @@ static HRESULT String_search(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DIS
     }
 
     if(!regexp) {
-        hres = create_regexp_var(ctx, arg, NULL, &regexp);
+        hres = create_regexp_var(ctx, argv, NULL, &regexp);
         if(FAILED(hres)) {
             SysFreeString(val_str);
             return hres;
@@ -1040,7 +1029,7 @@ static HRESULT String_search(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DIS
 }
 
 /* ECMA-262 3rd Edition    15.5.4.13 */
-static HRESULT String_slice(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT String_slice(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     const WCHAR *str;
@@ -1056,8 +1045,8 @@ static HRESULT String_slice(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISP
     if(FAILED(hres))
         return hres;
 
-    if(arg_cnt(dp)) {
-        hres = to_integer(ctx, get_arg(dp,0), ei, &d);
+    if(argc) {
+        hres = to_integer(ctx, argv, ei, &d);
         if(FAILED(hres)) {
             SysFreeString(val_str);
             return hres;
@@ -1077,8 +1066,8 @@ static HRESULT String_slice(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISP
         }
     }
 
-    if(arg_cnt(dp) >= 2) {
-        hres = to_integer(ctx, get_arg(dp,1), ei, &d);
+    if(argc >= 2) {
+        hres = to_integer(ctx, argv+1, ei, &d);
         if(FAILED(hres)) {
             SysFreeString(val_str);
             return hres;
@@ -1118,28 +1107,28 @@ static HRESULT String_slice(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISP
     return S_OK;
 }
 
-static HRESULT String_small(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT String_small(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     static const WCHAR smalltagW[] = {'S','M','A','L','L',0};
     return do_attributeless_tag_format(ctx, jsthis, retv, ei, smalltagW);
 }
 
-static HRESULT String_split(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT String_split(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     match_result_t *match_result = NULL;
     DWORD length, match_cnt, i, match_len = 0;
     const WCHAR *str, *ptr, *ptr2;
     BOOL use_regexp = FALSE;
-    VARIANT *arg, var;
+    VARIANT var;
     jsdisp_t *array;
     BSTR val_str, match_str = NULL;
     HRESULT hres;
 
     TRACE("\n");
 
-    if(arg_cnt(dp) != 1) {
+    if(argc != 1) {
         FIXME("unsupported args\n");
         return E_NOTIMPL;
     }
@@ -1148,12 +1137,11 @@ static HRESULT String_split(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISP
     if(FAILED(hres))
         return hres;
 
-    arg = get_arg(dp, 0);
-    switch(V_VT(arg)) {
+    switch(V_VT(argv)) {
     case VT_DISPATCH: {
         jsdisp_t *regexp;
 
-        regexp = iface_to_jsdisp((IUnknown*)V_DISPATCH(arg));
+        regexp = iface_to_jsdisp((IUnknown*)V_DISPATCH(argv));
         if(regexp) {
             if(is_class(regexp, JSCLASS_REGEXP)) {
                 use_regexp = TRUE;
@@ -1169,7 +1157,7 @@ static HRESULT String_split(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISP
         }
     }
     default:
-        hres = to_string(ctx, arg, ei, &match_str);
+        hres = to_string(ctx, argv, ei, &match_str);
         if(FAILED(hres)) {
             SysFreeString(val_str);
             return hres;
@@ -1250,14 +1238,14 @@ static HRESULT String_split(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISP
     return hres;
 }
 
-static HRESULT String_strike(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT String_strike(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     static const WCHAR striketagW[] = {'S','T','R','I','K','E',0};
     return do_attributeless_tag_format(ctx, jsthis, retv, ei, striketagW);
 }
 
-static HRESULT String_sub(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT String_sub(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     static const WCHAR subtagW[] = {'S','U','B',0};
@@ -1265,7 +1253,7 @@ static HRESULT String_sub(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPA
 }
 
 /* ECMA-262 3rd Edition    15.5.4.15 */
-static HRESULT String_substring(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT String_substring(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     const WCHAR *str;
@@ -1281,8 +1269,8 @@ static HRESULT String_substring(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags,
     if(FAILED(hres))
         return hres;
 
-    if(arg_cnt(dp) >= 1) {
-        hres = to_integer(ctx, get_arg(dp,0), ei, &d);
+    if(argc >= 1) {
+        hres = to_integer(ctx, argv, ei, &d);
         if(FAILED(hres)) {
             SysFreeString(val_str);
             return hres;
@@ -1292,8 +1280,8 @@ static HRESULT String_substring(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags,
             start = is_int32(d) ? min(length, d) : length;
     }
 
-    if(arg_cnt(dp) >= 2) {
-        hres = to_integer(ctx, get_arg(dp,1), ei, &d);
+    if(argc >= 2) {
+        hres = to_integer(ctx, argv+1, ei, &d);
         if(FAILED(hres)) {
             SysFreeString(val_str);
             return hres;
@@ -1326,7 +1314,7 @@ static HRESULT String_substring(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags,
 }
 
 /* ECMA-262 3rd Edition    B.2.3 */
-static HRESULT String_substr(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT String_substr(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     BSTR val_str;
@@ -1342,8 +1330,8 @@ static HRESULT String_substr(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DIS
     if(FAILED(hres))
         return hres;
 
-    if(arg_cnt(dp) >= 1) {
-        hres = to_integer(ctx, get_arg(dp,0), ei, &d);
+    if(argc >= 1) {
+        hres = to_integer(ctx, argv, ei, &d);
         if(FAILED(hres)) {
             SysFreeString(val_str);
             return hres;
@@ -1353,8 +1341,8 @@ static HRESULT String_substr(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DIS
             start = is_int32(d) ? min(length, d) : length;
     }
 
-    if(arg_cnt(dp) >= 2) {
-        hres = to_integer(ctx, get_arg(dp,1), ei, &d);
+    if(argc >= 2) {
+        hres = to_integer(ctx, argv+1, ei, &d);
         if(FAILED(hres)) {
             SysFreeString(val_str);
             return hres;
@@ -1380,14 +1368,14 @@ static HRESULT String_substr(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DIS
     return hres;
 }
 
-static HRESULT String_sup(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT String_sup(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     static const WCHAR suptagW[] = {'S','U','P',0};
     return do_attributeless_tag_format(ctx, jsthis, retv, ei, suptagW);
 }
 
-static HRESULT String_toLowerCase(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT String_toLowerCase(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     const WCHAR* str;
@@ -1417,7 +1405,7 @@ static HRESULT String_toLowerCase(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags
     return S_OK;
 }
 
-static HRESULT String_toUpperCase(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT String_toUpperCase(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     const WCHAR* str;
@@ -1447,28 +1435,28 @@ static HRESULT String_toUpperCase(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags
     return S_OK;
 }
 
-static HRESULT String_toLocaleLowerCase(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT String_toLocaleLowerCase(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     FIXME("\n");
     return E_NOTIMPL;
 }
 
-static HRESULT String_toLocaleUpperCase(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT String_toLocaleUpperCase(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     FIXME("\n");
     return E_NOTIMPL;
 }
 
-static HRESULT String_localeCompare(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT String_localeCompare(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     FIXME("\n");
     return E_NOTIMPL;
 }
 
-static HRESULT String_value(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT String_value(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     StringInstance *This = string_from_vdisp(jsthis);
@@ -1550,18 +1538,18 @@ static const builtin_info_t String_info = {
 
 /* ECMA-262 3rd Edition    15.5.3.2 */
 static HRESULT StringConstr_fromCharCode(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags,
-        DISPPARAMS *dp, VARIANT *retv, jsexcept_t *ei)
+        unsigned argc, VARIANT *argv, VARIANT *retv, jsexcept_t *ei)
 {
     DWORD i, code;
     BSTR ret;
     HRESULT hres;
 
-    ret = SysAllocStringLen(NULL, arg_cnt(dp));
+    ret = SysAllocStringLen(NULL, argc);
     if(!ret)
         return E_OUTOFMEMORY;
 
-    for(i=0; i<arg_cnt(dp); i++) {
-        hres = to_uint32(ctx, get_arg(dp, i), ei, &code);
+    for(i=0; i<argc; i++) {
+        hres = to_uint32(ctx, argv+i, ei, &code);
         if(FAILED(hres)) {
             SysFreeString(ret);
             return hres;
@@ -1579,7 +1567,7 @@ static HRESULT StringConstr_fromCharCode(script_ctx_t *ctx, vdisp_t *jsthis, WOR
     return S_OK;
 }
 
-static HRESULT StringConstr_value(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT StringConstr_value(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     HRESULT hres;
@@ -1590,8 +1578,8 @@ static HRESULT StringConstr_value(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags
     case INVOKE_FUNC: {
         BSTR str;
 
-        if(arg_cnt(dp)) {
-            hres = to_string(ctx, get_arg(dp, 0), ei, &str);
+        if(argc) {
+            hres = to_string(ctx, argv, ei, &str);
             if(FAILED(hres))
                 return hres;
         }else {
@@ -1607,10 +1595,10 @@ static HRESULT StringConstr_value(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags
     case DISPATCH_CONSTRUCT: {
         jsdisp_t *ret;
 
-        if(arg_cnt(dp)) {
+        if(argc) {
             BSTR str;
 
-            hres = to_string(ctx, get_arg(dp, 0), ei, &str);
+            hres = to_string(ctx, argv, ei, &str);
             if(FAILED(hres))
                 return hres;
 
diff --git a/dlls/jscript/vbarray.c b/dlls/jscript/vbarray.c
index baa5be2587d..87bdf88f994 100644
--- a/dlls/jscript/vbarray.c
+++ b/dlls/jscript/vbarray.c
@@ -44,7 +44,7 @@ static inline VBArrayInstance *vbarray_this(vdisp_t *jsthis)
     return is_vclass(jsthis, JSCLASS_VBARRAY) ? vbarray_from_vdisp(jsthis) : NULL;
 }
 
-static HRESULT VBArray_dimensions(script_ctx_t *ctx, vdisp_t *vthis, WORD flags, DISPPARAMS *dp,
+static HRESULT VBArray_dimensions(script_ctx_t *ctx, vdisp_t *vthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     VBArrayInstance *vbarray;
@@ -60,11 +60,11 @@ static HRESULT VBArray_dimensions(script_ctx_t *ctx, vdisp_t *vthis, WORD flags,
     return S_OK;
 }
 
-static HRESULT VBArray_getItem(script_ctx_t *ctx, vdisp_t *vthis, WORD flags, DISPPARAMS *dp,
+static HRESULT VBArray_getItem(script_ctx_t *ctx, vdisp_t *vthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     VBArrayInstance *vbarray;
-    int i, *indexes, size;
+    int i, *indexes;
     VARIANT out;
     HRESULT hres;
 
@@ -74,16 +74,15 @@ static HRESULT VBArray_getItem(script_ctx_t *ctx, vdisp_t *vthis, WORD flags, DI
     if(!vbarray)
         return throw_type_error(ctx, ei, JS_E_VBARRAY_EXPECTED, NULL);
 
-    size = arg_cnt(dp);
-    if(size < SafeArrayGetDim(vbarray->safearray))
+    if(argc < SafeArrayGetDim(vbarray->safearray))
         return throw_range_error(ctx, ei, JS_E_SUBSCRIPT_OUT_OF_RANGE, NULL);
 
-    indexes = heap_alloc(sizeof(int)*size);
+    indexes = heap_alloc(sizeof(int)*argc);
     if(!indexes)
         return E_OUTOFMEMORY;
 
-    for(i=0; i<size; i++) {
-        hres = to_int32(ctx, get_arg(dp, i), ei, indexes+i);
+    for(i=0; i<argc; i++) {
+        hres = to_int32(ctx, argv+i, ei, indexes+i);
         if(FAILED(hres)) {
             heap_free(indexes);
             return hres;
@@ -103,7 +102,7 @@ static HRESULT VBArray_getItem(script_ctx_t *ctx, vdisp_t *vthis, WORD flags, DI
     return hres;
 }
 
-static HRESULT VBArray_lbound(script_ctx_t *ctx, vdisp_t *vthis, WORD flags, DISPPARAMS *dp,
+static HRESULT VBArray_lbound(script_ctx_t *ctx, vdisp_t *vthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     VBArrayInstance *vbarray;
@@ -116,8 +115,8 @@ static HRESULT VBArray_lbound(script_ctx_t *ctx, vdisp_t *vthis, WORD flags, DIS
     if(!vbarray)
         return throw_type_error(ctx, ei, JS_E_VBARRAY_EXPECTED, NULL);
 
-    if(arg_cnt(dp)) {
-        hres = to_int32(ctx, get_arg(dp, 0), ei, &dim);
+    if(argc) {
+        hres = to_int32(ctx, argv, ei, &dim);
         if(FAILED(hres))
             return hres;
     } else
@@ -134,7 +133,7 @@ static HRESULT VBArray_lbound(script_ctx_t *ctx, vdisp_t *vthis, WORD flags, DIS
     return S_OK;
 }
 
-static HRESULT VBArray_toArray(script_ctx_t *ctx, vdisp_t *vthis, WORD flags, DISPPARAMS *dp,
+static HRESULT VBArray_toArray(script_ctx_t *ctx, vdisp_t *vthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     VBArrayInstance *vbarray;
@@ -182,7 +181,7 @@ static HRESULT VBArray_toArray(script_ctx_t *ctx, vdisp_t *vthis, WORD flags, DI
     return S_OK;
 }
 
-static HRESULT VBArray_ubound(script_ctx_t *ctx, vdisp_t *vthis, WORD flags, DISPPARAMS *dp,
+static HRESULT VBArray_ubound(script_ctx_t *ctx, vdisp_t *vthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     VBArrayInstance *vbarray;
@@ -195,8 +194,8 @@ static HRESULT VBArray_ubound(script_ctx_t *ctx, vdisp_t *vthis, WORD flags, DIS
     if(!vbarray)
         return throw_type_error(ctx, ei, JS_E_VBARRAY_EXPECTED, NULL);
 
-    if(arg_cnt(dp)) {
-        hres = to_int32(ctx, get_arg(dp, 0), ei, &dim);
+    if(argc) {
+        hres = to_int32(ctx, argv, ei, &dim);
         if(FAILED(hres))
             return hres;
     } else
@@ -213,7 +212,7 @@ static HRESULT VBArray_ubound(script_ctx_t *ctx, vdisp_t *vthis, WORD flags, DIS
     return S_OK;
 }
 
-static HRESULT VBArray_value(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DISPPARAMS *dp,
+static HRESULT VBArray_value(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
     FIXME("\n");
@@ -275,10 +274,9 @@ static HRESULT alloc_vbarray(script_ctx_t *ctx, jsdisp_t *object_prototype, VBAr
     return S_OK;
 }
 
-static HRESULT VBArrayConstr_value(script_ctx_t *ctx, vdisp_t *vthis, WORD flags, DISPPARAMS *dp,
+static HRESULT VBArrayConstr_value(script_ctx_t *ctx, vdisp_t *vthis, WORD flags, unsigned argc, VARIANT *argv,
         VARIANT *retv, jsexcept_t *ei)
 {
-    VARIANT *arg;
     VBArrayInstance *vbarray;
     HRESULT hres;
 
@@ -286,21 +284,21 @@ static HRESULT VBArrayConstr_value(script_ctx_t *ctx, vdisp_t *vthis, WORD flags
 
     switch(flags) {
     case DISPATCH_METHOD:
-        if(arg_cnt(dp)<1 || V_VT((arg = get_arg(dp, 0)))!=(VT_ARRAY|VT_VARIANT))
+        if(argc<1 || V_VT(argv) != (VT_ARRAY|VT_VARIANT))
             return throw_type_error(ctx, ei, JS_E_VBARRAY_EXPECTED, NULL);
 
-        hres = VariantCopy(retv, arg);
+        hres = VariantCopy(retv, argv);
         return hres;
 
     case DISPATCH_CONSTRUCT:
-        if(arg_cnt(dp)<1 || V_VT((arg = get_arg(dp, 0)))!=(VT_ARRAY|VT_VARIANT))
+        if(argc<1 || V_VT(argv) != (VT_ARRAY|VT_VARIANT))
             return throw_type_error(ctx, ei, JS_E_VBARRAY_EXPECTED, NULL);
 
         hres = alloc_vbarray(ctx, NULL, &vbarray);
         if(FAILED(hres))
             return hres;
 
-        hres = SafeArrayCopy(V_ARRAY(arg), &vbarray->safearray);
+        hres = SafeArrayCopy(V_ARRAY(argv), &vbarray->safearray);
         if(FAILED(hres)) {
             jsdisp_release(&vbarray->dispex);
             return hres;