It must also have the following features:

It must contain three control groups named: Patties, Toppings and Side

The patties control group must contain a listbox with three options: Single$-$Burger,

Double$-$Burger and Triple Burger.

A Single$-$Burger adds $$2\mathrm{.}50$ to the cost of the order.

A Double$-$Burger adds $$3\mathrm{.}50$ to the cost of the order.

A Triple$-$Burger adds $$4\mathrm{.}00$ to the cost of the order.

Only one item may be selected from the listbox.

The Toppings control group contains five checkboxes Lettuce, Tomato, Onion,

Ketchup and Mustard. Any of these may be checked. Each one adds $$0\mathrm{.}25$ to the

order.

The Side control group contails three radio buttons: Fries, Salad and No Side.

Selecting Fries adds $$3\mathrm{.}25$ to the order.

Selecting Salad adds $$5\mathrm{.}25$ to the order.

Selecting $"$No Side" doesn't change the value of the order.

Clicking the "Total" button causes the total of all the selected items to appear in the

label beside it$.$