public static void InsertCustomerDAL(KHACHHANG temp)
        {
            temp.XoaDuLieu = false;
            db.KHACHHANGs.InsertOnSubmit(temp);

            db.SubmitChanges();
        }
        //kiểm tra lại
        public static void UpdateCustomerDAL(KHACHHANG item)
        {
            var query = db.KHACHHANGs.Single(sa => sa.MaKH == item.MaKH);
            query.HoTen = item.HoTen;
            query.DiaChi = item.DiaChi;
            query.DienThoai = item.DienThoai;
            query.Email = item.Email;
            query.SoTienNo = item.SoTienNo;

            db.SubmitChanges();
        }
 partial void UpdateKHACHHANG(KHACHHANG instance);
 partial void DeleteKHACHHANG(KHACHHANG instance);
 partial void InsertKHACHHANG(KHACHHANG instance);