var timeout	= 300; 
var closetimer	= 0; 
var navlinkitem	= 0;

// open hidden layer
function MenuOpen(id)
{	
	// cancel close timer
	cancelclosetimer();

	// Close the previous menu opened
	if(navlinkitem) navlinkitem.style.visibility = 'hidden';

	// Get the new menu and open it
	navlinkitem = document.getElementById(id);
	navlinkitem.style.visibility = 'visible';

}
// Close the menu showed
function closenav()
{
	if(navlinkitem) navlinkitem.style.visibility = 'hidden';
}

// Close the menu timer
function closenavtimer()
{
	closetimer = window.setTimeout(closenav, timeout);
}

// Cancel the menu close timer
function cancelclosetimer()
{
	if(closetimer)
	{
		window.clearTimeout(closetimer);
		closetimer = null;
	}
}

// Close the menu when onclick
document.onclick = closenav;