You can't directly call a VBScript function from jQuery/JavaScript/AJAX per se, but you could just pass a URL variable that triggers your ASP code to run a specific VBScript function and then stop.
I'm not too familiar with the jQuery ajax function, but if you specified something like the following:
.ajax({
type: 'GET',
url: '<%= Request.ServerVariables("SCRIPT_NAME") %>?u=' + usr,
...
});
It should call your page again with the username passed as the u
query string variable. Then, somewhere near the start of your ASP code, you'd want to do something like this:
<%
Dim strUser
strUser = Request.QueryString("u")
If Len(strUser) > 0 Then
' Write an ajax response based on this user...
Response.Write ...
' Stop processing...
Response.End
End If
%>