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

function tc_open(id) {	
	tc_cancelclose();
	if(ddmenuitem) ddmenuitem.style.visibility = 'hidden';
	ddmenuitem = document.getElementById(id);
	ddmenuitem.style.visibility = 'visible';
}

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

function tc_closetime() {
	closetimer = window.setTimeout(tc_close, timeout);
}

function tc_cancelclose() {
	if(closetimer) {
		window.clearTimeout(closetimer);
		closetimer = null;
	}
}

document.onclick = tc_close;