protected void Page_Load(object sender, EventArgs e) { string rawId = Request.QueryString["ProductID"]; int productId; if (!String.IsNullOrEmpty(rawId) && int.TryParse(rawId, out productId)) { using (ShoppingCartActions usersShoppingCart = new ShoppingCartActions()) { usersShoppingCart.AddtoCart(Convert.ToInt16(rawId)); } } else { Debug.Fail("ERRO : We should never get to AddToCart.aspx without a" + "ProductId."); throw new Exception("ERRO : It is illegal to load AddToCart.aspx " + "without setting a ProductId."); } Response.Redirect("ShoppingCart.aspx"); }