var timeout	= 500;
var closetimer = 0;
var currentmenu = 0;
function openmenu(id)
{	
	cancelclosemenu();
	if(currentmenu) currentmenu.style.visibility = 'hidden';
	currentmenu = document.getElementById(id);
	currentmenu.style.visibility = 'visible';

}
function close()
{
	if(currentmenu) currentmenu.style.visibility = 'hidden';
}
function closemenu()
{
	closetimer = window.setTimeout(close, timeout);
}
function cancelclosemenu()
{
	if(closetimer)
	{
		window.clearTimeout(closetimer);
		closetimer = null;
	}
}
document.onclick = closemenu;