var timeout	= 150;
var closetimer	= 0;
var ddmenuitem	= 0;

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

	// close old layer
	if(ddmenuitem) ddmenuitem.style.visibility = 'hidden';
	
	if(document.getElementById(id) != null){
		var name = navigator.appName;
	
		// get new layer and show it
		ddmenuitem = document.getElementById(id);
		ddmenuitem.style.visibility = 'visible';
		var divID = id.substring(0, 4);
		document.getElementById(divID).appendChild(ddmenuitem);	
	
		if(name == 'Netscape'){
			ddmenuitem.style.top = '93px';
		}	
	}
}

// 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;
	}
}

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