Problem with users and roles

Hello,
I am adding users to roles ,, but i think the users are not really connected to the role ??
One othe thing: does this code looks ok:
if (Page.User.Identity.IsAuthenticated == false)
        {
            Server.Transfer("Default.aspx");
        }
       
        if (Page.User.IsInRole("Admin")== true)
        {
            Server.Transfer("main.aspx");
        }
        string name = User.Identity.Name;
        user.Text = name;


Thank you in advance,

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