private void HienThiThongTinSanPham(String maSP)
{
int ma = int.Parse(maSP);
Product p = bus.HienThiThongTinSP(ma);
txtDonGia.Text = p.UnitPrice.Value.ToString();
}
private void HienThiThongTinSanPham(String maSP)
{
int ma = int.Parse(maSP);
Product p = busDH.HienThiThongTinSP(ma);
txtNCC.Text = p.Supplier.CompanyName;
txtDonGia.Text = p.UnitPrice.ToString();
txtLoaiSP.Text = p.Category.CategoryName;
txtGiamGia.Text = "0";
}