protected void Page_Load(object sender, EventArgs e)
        {
            SQLDataClass.getAllProducts();
            SQLDataClass.getAllCheckout();

            this.DataBind();
        }
        protected void Button4_Click(object sender, EventArgs e)
        {
            try
            {
                string productID   = txtID.Text;
                string productName = TextBox2.Text;
                string unitPrice   = txtPrice.Text;
                string quantity    = txtQuantity.Text;
                string cost        = txtGrandTotal.Text;


                SQLDataClass.CheckoutProduct(productID, productName, unitPrice, quantity, cost);

                SQLDataClass.getAllCheckout();
            }
            catch (Exception ex)
            {
            }
        }