(Restaurant Bill Calculator)
A restaurant wants an app that calculates a table's bill. The app should display all the menu items from Fig. 15.53 in four ComboBoxes. Each ComboBox should contain a category of food offered by the restaurant (Beverage, Appetizer, Main Course and Dessert).
The user can choose from one of these ComboBoxes to add an item to a table's bill. As each item is selected in the ComboBoxes, add the price of that item to the bill. The user can click the Clear Bill Button to restore the Subtotal:, Tax: and Total: fields to $0.00.