var timeout	= 500;
var closetimer	= 0;
var ddmenuitem	= 0;
function meopen(id){
	mecancelclosetime();
	if(ddmenuitem) ddmenuitem.style.visibility = 'hidden';
	ddmenuitem = document.getElementById(id);
	ddmenuitem.style.visibility = 'visible';
}
function meclose(){
	if(ddmenuitem) ddmenuitem.style.visibility = 'hidden';
}
function meclosetime(){
	closetimer = window.setTimeout(meclose, timeout);
}
function mecancelclosetime(){
	if(closetimer){
		window.clearTimeout(closetimer);
		closetimer = null;
	}
}
document.onclick = meclose;