var timeout    = 500;
var closetimer = 0;
var ddmenuitem = 0;

function nav_open() {  
	nav_canceltimer();
	nav_close();
	ddmenuitem = $(this).find('ul').css('visibility', 'visible');
}

function nav_close() {
	if (ddmenuitem) ddmenuitem.css('visibility', 'hidden');
}

function nav_timer() {
	closetimer = window.setTimeout(nav_close, timeout);
}

function nav_canceltimer() {  
	if(closetimer) {  
		window.clearTimeout(closetimer);
		closetimer = null;
	}
}

jQuery(document).ready(function () {
	jQuery('#nav > li').bind('mouseover', nav_open);
	jQuery('#nav > li').bind('mouseout', nav_timer);
});

document.onclick = nav_close;