Logout

Try this code:
protected void lnkbLogout_Click(object sender, EventArgs e)
{
FormsAuthentication.SignOut(); Session.Abandon(); HttpContext.Current.Response.Redirect("Login.aspx", true);
}

//--- another way

protected void LoginStatus1_LoggedOut(object sender, EventArgs e)
{
//FormsAuthentication.SignOut();
//Roles.DeleteCookie();
//Session.Clear();
}