The purpose of this section is to introduce you to the concepts involved in creating your own VA Smalltalk reusable parts. You will learn how to create a nonvisual part, define its public interface, and then use the part in an application. When you finish, you will have a visual part that enables you to record the number and finish time of a runner in a road race, and displays the total time it took for the runner to complete the race.

The completed visual part will look like the following: