Handling Session Timeout in Windows authentication

[jonefer]

Ever since updating my Website from VS 2003 to 2005, I began to notice that
my session variables become reset (expire) after 10-15 (minutes)

The solutions I read dealing with this timeout generally have to do with
'Forms Authentication' but I'm not using forms authentication.

I read that you can put the following code in Global.asax - (could someone
please specify exactly how to do this, I always get an 'Invalid application'
error-- but is this the best solution for my session variables expiring?)

Sub Session_Start(...)

If Session.IsNewSession Then

If Not IsNothing(Request.Headers("Cookie")) And
Request.Headers("Cookie").IndexOf("ASP.NET_SessionId") >= 0 Then
Response.redirect("timeout.htm")
End If

End If

End Sub