public static void SavePersistence(RadPersistenceManager rpm)
 {
     try
     {
         rpm.StorageProviderKey = Util.GetUserId();
         rpm.SaveState();
     }
     catch { }
 }
        public static void LoadPersistence(RadPersistenceManager rpm)
        {
            String user_id          = Util.GetUserId();
            String persistence_file = Util.path + @"\App_Data\" + user_id;

            if (File.Exists(persistence_file))
            {
                try
                {
                    rpm.StorageProviderKey = user_id;
                    rpm.LoadState();
                }
                catch { }
            }
        }