public void OnAuthorization(AuthorizationContext filterContext)
 {
     if (!filterContext.HttpContext.Session.IsLoggedIn())
     {
         if (CookieHelpers.Exists(SessionKey._appBP))
         {
             try
             {
                 HttpContext.Current.Session.RestoreSessionFromCookie();
             }
             catch (Exception)
             {
                 CookieHelpers.DeleteAll();
                 HttpContext.Current.Session.Clear();
             }
         }
         else
         {
             CookieHelpers.DeleteAll();
         }
     }
 }