When a user presses the designated help key (usually F1 in Windows applications), a HELP event goes to the field-level widget with input focus in the current frame. If there is no trigger on the field-level widget, the HELP event goes to the current frame. The HELP event continues to move to the next level in the widget hierarchy, as shown in the following figure. If the help event does not find an associated widget, it runs applhelp.p, the OpenEdge help calling interface. This procedure, applhelp.p, in <install-dir>\src\, displays the message, "No application help is available."

The following figure depicts the behavior of the ABL HELP event.