//document.execCommand("BackgroundImageCache", false, true);

var Dom = YAHOO.util.Dom, Event = YAHOO.util.Event;

Event.onContentReady("nav", function () {
var oMenuBar = new YAHOO.widget.MenuBar("nav", { 
											autosubmenudisplay: true,
											showdelay: 0,
											hidedelay: 750,
											lazyload: true,
											iframe: true});
oMenuBar.render();
});