1. Open an Applications Browser or Application Browser.

2. Select the application that will contain the new class.

3. If the class you want to subclass from is not in the list of classes, select Visibility > Add Prerequisite Classes from the Classes menu. The names of all classes used by the prerequisites and subapplications of the containing application are added to the list of classes.

4. From the list of classes, select the class you want to subclass from. For example, select Object.

5. From the Classes menu, select Add > Subclass. A window opens, prompting you to name the new subclass.

6. Type the name of the new class. For example, type in TestClass. Then select OK. A window opens, prompting you to select subclass, variableSubclass, or some other type of subclass.

7. Select the type of subclass for the new class. You will most likely want subclass.

8. Click on OK. The new class is added as a subclass of the selected class. The new class inherits the behavior of the superclass, meaning that the new class can use the methods defined in the superclass. You can add to or change the inherited behavior by adding new methods to it.