<oTopBar>:getNext() --> nPosition

        Returns a numeric value that indicates the position within the top
        bar menu of the next selectable item.  getNext() returns 0 in the
        event that the current item is the last selectable item or the top
        bar menu does not contain a selectable item.

        getNext() is a method of the TopBarMenu class that is used for
        determining the position of the next selectable item in a top bar
        menu.  getNext() searches for the next selectable item starting at
        the item immediately after the current item.  The term selectable is
        defined as a menu item that is enabled and whose caption is not a
        menu separator.

        Note:  getNext() does not change the currently selected menu item.
        In order to change the currently selected top bar menu item, you must
        call the TopBarMenu:select() method.