private void Add_Product_button_Click(object sender, RoutedEventArgs e)
        {
            string product_Code = Product_Code_Textbox.Text.ToString();
            string product_Name = Product_Name_textBox.Text.ToString();

            double list_price, unit_price;
            bool   listPrice, unitPrice, reorderLevel, reorderQuant, onHand;
            int    reorder_level, reorder_quant, on_Hand;

            CheckTextBoxes(out list_price, out listPrice, out unit_price, out unitPrice, out reorder_level, out reorderLevel, out reorder_quant, out reorderQuant, out on_Hand, out onHand);

            //Ensure all fields have actually been filled out
            if (listPrice && unitPrice && reorderLevel && reorderQuant && onHand && product_Code.Length >= 4 && product_Name.Length >= 1 && category_comboBox.SelectedIndex >= 0)
            {
                //Create and Add the product to the database
                string  category = category_comboBox.Text.ToString();
                Product product  = new Product(product_Name, product_Code, category, list_price, unit_price);

                string    location      = Location_comboBox.Text.ToString();
                Inventory inventoryitem = new Inventory(product_Name, location, product_Code, on_Hand, reorder_level, reorder_quant);

                ProductLocation pl = (ProductLocation)Location_comboBox.SelectedItem;
                ProductLocation.ChangeItemAtLocation(pl.Product_Location, product_Code, on_Hand);

                product.Save();
                inventoryitem.Save();

                //Reset all Textboxes to blank;
                ResetBoxesToBlank();
                listBox.ItemsSource = Product.GetAll(); //refresh the listbox items
                List <ProductLocation> locations = ProductLocation.GetAllEmpty();
                Location_comboBox.Items.Clear();
                foreach (ProductLocation item in locations)
                {
                    Location_comboBox.Items.Add(item);
                }
            }
        }