This feature is usefull for menu with many items in the submenu. NlsMenu support default scroll (browser's vertical scrollbar) and custom scroll.

var menuArchive=menuMgr.createMenu("archives");

//set max height of menu, if the total height
//of items exceeds maxHeight, the scrollbar will be displayed.

menuArchive.maxHeight=250;

//set scroll type, 1 for default, 2 for custom scroll
menuArchive.scrollType=1;