In my C# class I am supposed to create a form app that is an order form for some shoes. It has text boxes for Name, Address, Subtotal, Shipping and total. And it has a radio button for regular shipping and one for express shipping, and a button to submit and a button to clear. And it has list boxes for the size and a list box for the amount. How do i the total list box to display the list box amount for shoes multiplied by the cost of the shoes?