protected void submitButton_Click(object sender, EventArgs e)
    {
        //get the productModle.cs function
        ProductModel pm = new ProductModel();
        //call the createProduct() method
        Product product = createProduct();
        //add new product
        if (String.IsNullOrWhiteSpace(Request.QueryString["id"]))
        {
            //display the resultmessage and call the InSetProduct method from pm which is the productModle.cs
            productMessageLabel.Text = pm.InSetProduct(product);

        }
        //modify existing model update
        else
        {
            //get the existing product id
            int id = Convert.ToInt32(Request.QueryString["id"]);
            //use update method
            productMessageLabel.Text = pm.UpdateProduct(id, product);
        }
    }