Session checking in _Layout page in mvc

Question

In my _Layout page, I have added following code before @RenderBody()

 @if (Session["UserID"].ToString() != "" || Session["UserID"]!=null)
 {
      if (Session["RoleID"].ToString() == "2")
      {
           //menus here
      }

}
else
{
    Response.Redirect("~/Account/login");
}

 but still it is not redirecting to login when Session["UserID"] is empty & it is rendering @RenderBody()

 

I downt want to call @RenderBody() is  Session["UserID"] is empty.

 

please help me out