public static bool KiemTraSLT(string MaSP, int SL)
        {
            DataTable dt = SanPhamBUS.DanhSachSPTheoMa(MaSP);
            int       soluongton = 0, hieu;

            foreach (DataRow row in dt.Rows)
            {
                soluongton = (int)row["SoLuongTon"];
            }
            hieu = soluongton - SL;
            if (hieu < 0)
            {
                return(false);
            }
            else
            {
                return(true);
            }
        }
        public bool suaSL(DataTable dtChiTietDonHang)
        {
            foreach (DataRow CTDonHang in dtChiTietDonHang.Rows)
            {
                SanPhamPublic SP    = new SanPhamPublic();
                SanPhamBUS    spbus = new SanPhamBUS();
                try
                {
                    SP.MASP = CTDonHang.Field <string>("MaSP");

                    int slcu = spbus.LaySanPham(SP).SOLUONG;
                    int slt  = CTDonHang.Field <int>("SoLuong");
                    SP.SOLUONG = slcu - slt;
                    spbus.capnhatsoluong(SP);
                }
                catch (Exception ex)
                {
                    throw ex;
                }
            }
            return(true);
        }