var timeout	= 500;
var chkCloseMenu	= 0;
var currentMenuItem	= 0;

function tabOpen(id)
{	
	cancelPrevCloseTime();
	if(currentMenuItem) 
		currentMenuItem.style.visibility = 'hidden';

	currentMenuItem = document.getElementById(id);
	currentMenuItem.style.visibility = 'visible';
}

function menuCloseTime()
{
	chkCloseMenu = window.setTimeout(finalCloseMenu, timeout);
}

function cancelPrevCloseTime()
{
	if(chkCloseMenu)
	{
		window.clearTimeout(chkCloseMenu);
		chkCloseMenu = null;
	}
}

function finalCloseMenu()
{
	if(currentMenuItem) currentMenuItem.style.visibility = 'hidden';
}

document.onclick = finalCloseMenu;