private void BtnDelete_Click(object sender, RoutedEventArgs e)
        {
            MessageBoxResult mbResult = MessageBox.Show("Delete Confirmation", "Are you sure?", MessageBoxButton.YesNo);

            if (mbResult == MessageBoxResult.Yes)
            {
                mw.total.RemoveAt(index);
                mw.items.RemoveAt(index);

                OrderCounter();

                mw.ClearOrder();
                mw.Load_dgItemList();
                mw.Cart_Total();

                this.Close();
            }
        }
        // button to enter order item into List<Item> items
        private void BtnEnter_Click(object sender, RoutedEventArgs e)
        {
            ComputeItemTotal();

            main.items.Add(new Item()
            {
                OrderNumber = main.orderCounter,
                Quantity    = quantity,
                ItemName    = row["Item"].ToString(),
                ItemTotal   = itemTotal,
                Code        = row["Code"].ToString(),
                Price       = Convert.ToInt32(row["Price"])
            });

            main.total.Add(itemTotal);
            main.orderCounter++;
            main.ClearOrder();
            main.Load_dgItemList();
            main.Cart_Total();

            this.Close();
        }