How To: add a -NONE option to a form menu INPUT CHOICE
The form menu INPUT widget does not have a -NONE option; how can it be added to an INPUT widget using the CHOICE option?
Add an option called _NONE_ to the list of choices for that widget. In the return string for that widget add the following action:
&IF [QUOTE %< widget_variable >%] = '_NONE_' &THEN &SET %< widget_variable >%
This allows the variable to be set and exist while containing a null.