// GET: QuanLyProduct/Edit/5
        public ActionResult Edit(int id)
        {
            //if (id == null)
            //{
            //    Response.StatusCode = 404;
            //    return null;
            //}
            var sp = ProductBus.GetProduct(id);

            if (sp == null)
            {
                HttpNotFound();
            }
            ViewBag.CategogyID     = new SelectList(ProductBus.GetListCategogy(), "ID", "CategogyName", sp.CategogyID);
            ViewBag.ManufacturerID = new SelectList(ProductBus.GetListManufacturer(), "ID", "ManufacturerName", sp.ManufacturerID);
            ViewBag.ThongBao       = "";
            ViewBag.ListImage      = ProductBus.getListImage(id).ToList();
            return(View(sp));
        }