Returns the handle of a widget at a specified tab position in a field group.
You can use the MOVE-AFTER-TAB-ITEM( ) and MOVE-BEFORE-TAB-ITEM( ) methods to change the tab position of fields at the field level, and the FIRST-TAB-ITEM and LAST-TAB-ITEM attributes to change the tab positions at the field group level.
If the widget returned is a frame, the specified tab position includes the tab positions of all tab-order widgets contained by the frame. For more information on how frames owned by a field group participate in the tab order of that field group, see the
FRAME widget reference entry.