public string SinhMaTuDong(string tenbang, string tenma, string MaBatDau)
        {
            DungLuongCtrl dlCtrl = new DungLuongCtrl();
            int           id     = 0;
            bool          dung   = false;
            string        ma     = "";
            DataTable     dt     = new DataTable();

            while (dung == false)
            {
                dt = CheckID(tenbang, tenma, MaBatDau + id.ToString());

                if (dt.Rows.Count == 0)
                {
                    dung = true;
                }
                else
                {
                    id++;

                    dung = false;
                }
            }
            ma = MaBatDau + id.ToString();
            return(ma);
        }