public ActionResult DeleteProduct(int id)
        {
            bool Xoasanpham = sanpham.DeleteProduct(id);

            if (Xoasanpham == true)
            {
                return(RedirectToAction("Product", new { page = 1 }));
            }
            else
            {
                return(RedirectToAction("Product", new { page = 1 }));
            }
        }