The Menu displays scroll buttons for submenus whose content does not fit within the visible area.
By default, submenus are automatically rendered to accommodate their entire content. If a submenu contains a large number of items, it might not fit vertically in the visible area. This occurs when a submenu's height exceeds the browser window's height (or the height of an IFRAME containing the menu). In such instances, scroll buttons are needed within the submenus. If scroll buttons are enabled, a submenu that does not fit the visible area automatically adjusts its height to fit the area and displays scroll buttons, allowing submenu items to be scrolled vertically.