Executing programs that display the drop down or drop list style of the combo-box control on Windows-based systems allows the user to actuate the drop down list by pressing the F4 key or clicking the control's down button.
However, on character-based systems without mouse support, clicking the control's down button is not an option and pressing the F4 key has no affect.
Character-based systems can be configured to react to the F4 key in a similar fashion as Windows by setting the following KEYSTROKE entry in the runtime's configuration file:
KEYSTROKE EDIT=TOGGLE-EDIT-MODE k4
Setting this variable will allow the user to deploy or retract the drop down list by pressing the F4 key. Alternately, this variable can be set in the COBOL program using the following syntax:
Set environment "KEYSTROKE" to "EDIT=TOGGLE-EDIT-MODE k4"
Additionally, keys other than the F4 key may be chosen. Further information on setting the KEYSTROKE variable may be found in the ACUCOBOL-GT User's Guide version 8.0, Chapter 4, Section 188.8.131.52.