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


//open hidden layer
function menuopen(id) { 
	
	//cancel close timer
  	menucancelclosetime();

	//close old layer
	if(ddmenuitem) ddmenuitem.style.visibility = 'hidden';


	//get new layer and show it
	ddmenuitem = document.getElementById(id);
	ddmenuitem.style.visibility = 'visible';

}


//close showed layer
function menuclose() { 

	if(ddmenuitem) ddmenuitem.style.visibility = 'hidden';
}

 
// go close timer
function menuclosetime() {
	closetimer = window.setTimeout(menuclose, timeout);
}



//cancel close timer
function menucancelclosetime() { 
  	if (closetimer) {
		window.clearTimeout(closetimer);
		closetimer = null;
	}
}

// close layer when click-out
document.onclick = menuclose;