This event occurs when the user scrolls a wheelmouse away from the computer screen. The expected behavior from the runtime is to scroll the LIST upwards, that is, to fill in items from the top of the list. EVENT-DATA-1 indicates if any virtual keys have been pressed at the same time as the scroll, and EVENT-DATA-2 indicates the number of lines that should be scrolled on each wheelmouse event. See MSG-PAGED-NEXT-WHEEL (value16439) for more information.