When a user who does not belong to admin role is already logged in and has tried accessing the admin section, unfortunately he will be again forwarded to the Login page. Refer to Figure 2.

Figure 2 – NotAuthorized Problem

Instead, if a "Not authorized" page is displayed, it will be more appropriate for this scenario.

We can achieve this by redirecting the user to NotAuthorized page by including the below code in Page_Load event of Login page.

Listing 12 - Not Authorized Page Redirection

if (User.Identity.IsAuthenticated && Request.QueryString["ReturnUrl"] != null)
{
  Response.Redirect("NotAuthorized.aspx");
}

The above code checks whether the user is authenticated and ReturnUrl is not null through which we can confirm that the user is trying to access a resource which he does not have access after authenticating.