Web Forms :: Session - URL Routing To Route User To His Profile Page

I am using URL Routing to route user to his profile page, which is a child page. Now the problem is that all the images, javascripts references are distorted when i user the url to reach that page whether logged in or not logged in (both the cases). But after reaching this page when i login from this page thru my modal popup login control, all the references seem to work fine. It is to be noted that i am still in that same page which i reached after url routing. So upon logging from here the whole page works and displays fine.

How come the references are automatically adjusted when i am logging in from this page and are not referenced when i log in from other page and route here or when i am logged out?

Global.asax code:

void Application_Start(object sender, EventArgs e)
{
RegisterRoutes(RouteTable.Routes);
}
public static void RegisterRoutes(RouteCollection routes)
{
routes.Add("UseridRoute", new Route
(
"profile/{user}",
new CustomRouteHandler("~/UserProfile.aspx")
));
}