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

// open hidden layer
function mopen(id, caller)
{	
	// cancel close timer
	mcancelclosetime();

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

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

	ddmenuitem.style.left = findPos(caller)[0] + 'px';
	ddmenuitem.style.top = findPos(caller)[1] + caller.offsetHeight + 'px';
}
// close showed layer
function mclose()
{
	if(ddmenuitem) ddmenuitem.style.visibility = 'hidden';
}

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

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

function findPos(obj) 
{
	var curleft = curtop = 0;

	if (obj.offsetParent) 
	{
		do 
		{
			curleft += obj.offsetLeft;
			curtop += obj.offsetTop;
		} 
		while (obj = obj.offsetParent);
	}
	return [curleft,curtop];
}



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