private void AddBooks_Click(object sender, EventArgs e) { CustomerID = Convert.ToInt32(textBox1.Text); int NewSaleID = ControlObj.ReturnNextSaleID() + 1; var BookIDs = string.Join(",", CartPointer.Select(x => x.ToString()).ToArray()); if (String.IsNullOrEmpty(BookIDs)) { MessageBox.Show("Cart Is Empty"); return; } var BookIDStr = "( " + BookIDs + " )"; DataTable CartInfo = ControlObj.DisplayCart(BookIDStr); string TotalSalePrice = Convert.ToString(CartInfo.Compute("Sum(Price)", "")); //Add to Sales History ControlObj.AddSaleToHistory(Convert.ToString(NewSaleID), TotalSalePrice, Convert.ToString(CustomerID), BranchID.ToString(), EmpID.ToString()); //Did The Sold books foreach (int id in CartPointer) { ControlObj.FillSoldBooks(Convert.ToString(NewSaleID), Convert.ToString(id)); } MessageBox.Show("Transaction Complete"); }