calculates the total annual compensation of a salesperson

Write a Java GUI application using NetBeans IDE that calculates the total annual compensation of a salesperson. Consider the following 1. The calculator should allow user to enter the amount of sales. 2. The calculator should allow user to select the level of commission rate from a list of pre-defined commission rate. The 3 choices in the list are:
Add a percentage here
Add a percentage here
Add a percentage here

The calculator should display the amount of commission in dollar, based on the amount of sales entered and the commission rate selected.

The application should have at least one class, in addition to the application's controlling class.

There should be proper documentation in the source code.