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

//open hidden layer
function mopen(id)
{	
	//cancel closetimer
	mcancelclosetime();

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

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

}
//close visible layer
function mclose()
{
	if(ddmenuitem) ddmenuitem.style.visibility = 'hidden';
}

//closetimer
function mclosetime()
{
	closetimer = window.setTimeout(mclose, timeout);
}

//abort close timer
function mcancelclosetime()
{
	if(closetimer)
	{
		window.clearTimeout(closetimer);
		closetimer = null;
	}
}
//close layer on click-out
document.onclick = mclose;