<oPopUp>:getFirst() --> nPosition

        getFirst() is a method of the PopUpMenu class that is used for
        determining the position of the first selectable item in a pop-up
        menu.  The term selectable is defined as a menu item that is enabled
        and whose caption is not a menu separator.

        Returns a numeric value that indicates the position within the pop-up
        menu of the first selectable item.  getFirst() returns 0 in the event
        that the pop-up menu does not contain a selectable item.

        Note:  getFirst() does not change the currently selected menu
        item.  In order to change the currently selected pop-up menu item,
        you must call the PopUpMenu:select() method.