protected void btnAdd_Click(object sender, EventArgs e) { try { if (!string.IsNullOrWhiteSpace(Request.QueryString["id"])) { string clientId = User.Identity.GetUserId(); if (clientId != null) { int productId = Convert.ToInt32(Request.QueryString["id"]); int amount = Convert.ToInt32(ddlAmount.SelectedValue); Purchase newPurchase = new Purchase { CustomerId = clientId, ProductId = productId, Amount = amount, DatePurchased = DateTime.Now, IsInCart = true }; PurchaseModel model = new PurchaseModel(); LabelResult.Text = model.AddPurchase(newPurchase); } else { Response.Redirect("~/Page/Account/login.aspx"); } } } catch (Exception) { LabelResult.Text = "Purchase Fail"; LabelResult.ForeColor = System.Drawing.Color.Red; } }