public ActionResult Edit(Product product)
        {
            try
            {
                Repository.Save(product);

                return RedirectToAction("Index");
            }
            catch
            {
                return View();
            }
        }
        public ActionResult Edit(Product product)
        {
            try
            {
                var existingProduct = DB.Products.Single(p => p.ProductID == product.ProductID);
                existingProduct.Name = product.Name;
                existingProduct.ProductNumber = product.ProductNumber;
                existingProduct.ListPrice = product.ListPrice;
                DB.SubmitChanges();

                return RedirectToAction("Index");
            }
            catch
            {
                return View();
            }
        }