public static SAN_PHAM ThanhToan(SAN_PHAM sp)
        {
            CHI_TIET_SAN_PHAM ctsp = ChiTietSanPham.LayChiTietSanPham(sp.MA_CHI_TIET_SAN_PHAM);

            sp.GIA_BAN = ctsp.GIA_BAN;
            sp.NGAY_BAT_DAU_BAO_HANH  = DateTime.Now;
            sp.NGAY_KET_THUC_BAO_HANH = DateTime.Now.AddMonths(Convert.ToInt32(ctsp.THOI_GIAN_BAO_HANH));
            sp.TRANG_THAI             = 1;
            SAN_PHAM.update(sp);
            return(sp);
        }
        public static int LayTongCong(List <SAN_PHAM> imei)
        {
            int tongCong = 0;

            for (int i = 0; i < imei.Count; i++)
            {
                SAN_PHAM tmp = imei[i];
                tongCong += ChiTietSanPham.LayChiTietSanPham(tmp.MA_CHI_TIET_SAN_PHAM).GIA_BAN;
            }
            return(tongCong);
        }
 public static int LayTongCong(SAN_PHAM imei)
 {
     return(ChiTietSanPham.LayChiTietSanPham(imei.MA_CHI_TIET_SAN_PHAM).GIA_BAN);
 }