URL Rewriting issue

Hi,

I m upgrading a vb.net application from 1.0 version to VS 2010. I want to set last part of URL fix as /Public/Main.aspx for whole application after user login till user logout from application, no matter which page he access from menu.

But i am  not able to do that i have tried several things like one of them:

Sub Application_BeginRequest(ByVal sender As Object, ByVal e As EventArgs)
Dim URL_path As String = HttpContext.Current.Request.Path
If (Not URL_path.Contains("/Public/Main.aspx") And Not URL_path.Contains("/Public/Login.aspx")) Then
Context.RewritePath("/Public/Main.aspx")
End If
End Sub

but it is not updating correct manner. It starts updating for Image url and when we click on menu then starts showing two windows on page with only menu control.

I can't check for each and every page, There are more than 100 page, and i want same url for every page.

Please help.