Added some environment variables documentation.

documentation/running.sgml

@@ -263,6 +263,29 @@ winspool</><entry>wnet</><entry>x11</>
         </para>
       </sect2>
     </sect1>
+
+    <sect1 id="environment-variables">
+      <title>Setting Windows/DOS environment variables</title>
+      <para>
+        Your program might require some environment variable to be set
+	properly in order to run successfully.
+	In this case you need to set this environment variable in the
+	Linux shell, since Wine will pass on the entire shell environment
+	variable settings to the Windows environment variable space.
+	Example for the bash shell (other shells may have a different syntax
+	!):
+        <screen>
+	  export MYENVIRONMENTVAR=myenvironmentvarsetting
+	</screen>
+	This will make sure your Windows program can access the
+	MYENVIRONMENTVAR environment variable once you start your program
+	using Wine.
+	If you want to have MYENVIRONMENTVAR set permanently, then you can
+	place the setting into /etc/profile, or also ~/.bashrc in the case of
+	bash.
+      </para>
+    </sect1>
+
   </chapter>
 
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