Before you can preview your application in test mode, it must have a Main Menu form. Also, you should have provided some method of navigation in your application. Typically, this would be push buttons or menus with scripts attached that open other forms in the dictionary. For information about using scripts to open forms and windows, refer to Controlling forms and windows.
To start test mode, choose Test Mode from the Debug menu. After a moment, your application will start. The Dexterity tool bar and menus will disappear. Any menus you have defined for your application will appear, along with the Debug menu. The Debug menu will appear as the rightmost menu.
When you have finished working with your application, simply choose Test Mode from the Debug menu. After a moment, you will return to Dexterity.