private void btnSave_Click(object sender, EventArgs e)
        {
            CustomerBO cbo = new CustomerBO();
            float      totalAmount;
            float      productPrice;

            switch (cmbProductName.Text)
            {
            case "Tost":
                productPrice        = 5; // birim fiyatı 5 tl
                totalAmount         = productPrice * (Convert.ToInt16(txtProductQuantity.Text));
                txtTotalAmount.Text = totalAmount.ToString() + " " + "TL";
                break;

            case "Hamburger":
                productPrice        = 7.5f; // birim fiyatı 7,5 tl
                totalAmount         = productPrice * (Convert.ToInt16(txtProductQuantity.Text));
                txtTotalAmount.Text = totalAmount.ToString() + " " + "TL";
                break;

            case "Cips":
                productPrice        = 6;// birim fiyatı 6 tl
                totalAmount         = productPrice * (Convert.ToInt16(txtProductQuantity.Text));
                txtTotalAmount.Text = totalAmount.ToString() + " " + "TL";
                break;

            case "Kola":
                productPrice        = 5;// birim fiyatı 5 tl
                totalAmount         = productPrice * (Convert.ToInt16(txtProductQuantity.Text));
                txtTotalAmount.Text = totalAmount.ToString() + " " + "TL";
                break;

            case "Fanta":
                productPrice        = 5;// birim fiyatı 5 tl
                totalAmount         = productPrice * (Convert.ToInt16(txtProductQuantity.Text));
                txtTotalAmount.Text = totalAmount.ToString() + " " + "TL";
                break;

            case "Soda":
                productPrice        = 4;// birim fiyatı 4 tl
                totalAmount         = productPrice * (Convert.ToInt16(txtProductQuantity.Text));
                txtTotalAmount.Text = totalAmount.ToString() + " " + "TL";
                break;
            }
            var customer = cbo.GetByRoomNumber(Convert.ToInt32(cmbRoomNumber.Text));

            switch (cmbProductName.Text)
            {
            case "Tost":
                customer.SoldToast = Convert.ToByte(txtProductQuantity.Text);
                break;

            case "Hamburger":
                customer.SoldHamburger = Convert.ToByte(txtProductQuantity.Text);
                break;

            case "Cips":
                customer.SoldChips = Convert.ToByte(txtProductQuantity.Text);
                break;

            case "Kola":
                customer.SoldCola = Convert.ToByte(txtProductQuantity.Text);
                break;

            case "Fanta":
                customer.SoldFanta = Convert.ToByte(txtProductQuantity.Text);
                break;

            case "Soda":
                customer.SoldSoda = Convert.ToByte(txtProductQuantity.Text);
                break;
            }

            if (cbo.AddProduct(customer))
            {
                MessageBox.Show("Ürün satışı başarılı");
            }
            else
            {
                MessageBox.Show("Bu odada müşteri yok");
            }
        }