A common method of requesting help from an application is by selecting help items from the application menu bar. The menu bar usually includes a help pull-down menu and contains menu items, such as:

  • Help Topics — Instruct the help engine to display the HTML Help Viewer for the specified help file
  • About or Version — Provide application copyright and version number information

The CHOOSE event occurs when a user chooses an option from a menu. In ABL, you use a CHOOSE event to code a trigger for menu items.

The following code example demonstrates a help trigger that executes when the user selects a menu item from the application's menu bar to access the help engine:

ON CHOOSE OF MENU-ITEM menu_help_contents DO:
  SYSTEM-HELP myhelp.chm CONTENTS.
END.