I'm not sure if this is supposed to work or if that is a feature which is not supported by VAX: given a .aspx file which contains C# code, the C# code is not syntax colored, none of the editing enhancements of VAX work.
On the other hand, the same .aspx page containing javascript or vbscript is recognized properly by VAX.
sample:
<%@ Import Namespace="System.Data.SqlClient" %>
<%@ Import Namespace="System.Data" %>
<%@ Page Language="C#" %>
<HTML>
<HEAD>
<TITLE>Login</TITLE>
<SCRIPT runat="server" Language="C#">
public void somfunc()
{
int a = 1; // comment
}
</SCRIPT>
<SCRIPT Language="javascript">
function somfunc()
{
var a = 1; // comment
}
</SCRIPT>
</HEAD>
<BODY>
</BODY>
</HTML>