/// <summary>
        /// Sinh ma doi tac, neuchua co thi gan la ID0001
        /// Neu co roi thi lay max + 1
        /// </summary>
        /// <returns>Ma tiep theo</returns>
        public static string GetNextMaKhachVIP()
        {
            try
            {
                string strMaxKey  = new Data.DM.KhachVIP().GetNextMaKhachVIP();
                string strNextKey = string.Empty;

                if (strMaxKey.Length >= 6)
                {
                    string sID = strMaxKey.Substring(2, 4);
                    long   ID  = long.Parse(sID);
                    ID += 1;
                    sID = ID.ToString();
                    while (sID.ToString().Length < 4)
                    {
                        sID = "0" + sID;
                    }
                    return("VI" + sID);
                }
                else
                {
                    return("VI0001"); // ma dau tien
                }
            }
            catch (Exception ex)
            {
                return(string.Empty);
            }
        }
        public List <KhachVIP> GetListOfKhachVIPs()
        {
            List <KhachVIP> lstKhachVIP = new List <KhachVIP>();
            DataTable       dt          = new DataTable();

            dt = new Data.DM.KhachVIP().GetDanhSachKhachVIPs(string.Empty);// lay ta ca
            if (dt.Rows.Count > 0)
            {
                foreach (DataRow dr in dt.Rows)
                {
                    KhachVIP objKhachVIP = new KhachVIP();
                    objKhachVIP.MaKhachVIP = StringTools.TrimSpace(dr["Ma_KhachVIP"].ToString());
                    objKhachVIP.Name       = StringTools.TrimSpace(dr["Name"].ToString());
                    objKhachVIP.Address    = StringTools.TrimSpace(dr["Address"].ToString());
                    objKhachVIP.Phones     = StringTools.TrimSpace(dr["Phones"].ToString());
                    objKhachVIP.Fax        = StringTools.TrimSpace(dr["Fax"].ToString());
                    objKhachVIP.Email      = StringTools.TrimSpace(dr["Email"].ToString());


                    objKhachVIP.Notes    = dr["Notes"].ToString();
                    objKhachVIP.IsActive = dr["IsActive"].ToString() == "1" ? true : false;

                    lstKhachVIP.Add(objKhachVIP);
                }
            }

            return(lstKhachVIP);
        }
        /// <summary>
        /// Lay thong tin cua khach VIP boi SoDienThoai
        /// </summary>
        /// <param name="PhoneNumber"></param>
        /// <returns></returns>
        public static KhachVIP GetKhachVIPByPhoneNumber(string PhoneNumber)
        {
            KhachVIP  objKhachVIP = new KhachVIP();
            DataTable dt          = new DataTable();

            dt = new Data.DM.KhachVIP().GetKhachVIPByPhoneNumber(PhoneNumber);
            if (dt.Rows.Count == 1)
            {
                objKhachVIP.MaKhachVIP = StringTools.TrimSpace(dt.Rows[0]["Ma_KhachVIP"].ToString());
                objKhachVIP.Name       = StringTools.TrimSpace(dt.Rows[0]["Name"].ToString());
                objKhachVIP.Address    = StringTools.TrimSpace(dt.Rows[0]["Address"].ToString());
                objKhachVIP.Phones     = StringTools.TrimSpace(dt.Rows[0]["Phones"].ToString());
                objKhachVIP.Fax        = StringTools.TrimSpace(dt.Rows[0]["Fax"].ToString());
                objKhachVIP.Email      = StringTools.TrimSpace(dt.Rows[0]["Email"].ToString());
                objKhachVIP.Notes      = dt.Rows[0]["Notes"].ToString();
                objKhachVIP.IsActive   = dt.Rows[0]["IsActive"].ToString() == "1" ? true : false;
            }
            dt.Dispose();
            dt = null;
            return(objKhachVIP);
        }