var timeout	= 500;
var closetimer	= 0;
var ttmenuitem	= 0;

// open hidden layer
function topen(id)
{	
	// cancel close timer
	tcancelclosetime();

	// close old layer
	if(ttmenuitem) ttmenuitem.style.display = 'none';

	// get new layer and show it
	ttmenuitem = document.getElementById(id);
	ttmenuitem.style.display = 'block';

}
// close showed layer
function tclose()
{
	if(ttmenuitem) ttmenuitem.style.display = 'none';
}

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

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

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