MVC Authorization Custom Error Page 401 and (Not found)404

1. Error 401 Authorization

public class Global : HttpApplication
    {
        void Application_Start(object sender, EventArgs e)
        {
            // Code that runs on application startup
            AreaRegistration.RegisterAllAreas();
            GlobalConfiguration.Configure(WebApiConfig.Register);
            FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
            RouteConfig.RegisterRoutes(RouteTable.Routes);         
        }

        protected void Application_EndRequest()
        {
            var context = new HttpContextWrapper(Context);
            if (context.Response.StatusCode == 401)
            {
                context.Response.Redirect("~/Home/Error2");
            }
        }
    }


2.   Error 404
 <customErrors mode="On">     
      <error statusCode="404" redirect="~/Home/Error"/>
    </customErrors>