var oldMenu;
var memOldMenu;

if (document.layers)
{
	window.captureEvents(Event.MOUSEDOWN);
	window.onmousedown = exitMenu;
}
else
{
	document.onmouseup = exitMenu;
}

function showLayer(menu)
{
	if (document.layers)
		document.layers[menu].visibility = "show";
	else
		document.all[menu].style.visibility = "visible";
}

function hideLayer(menu)
{
	if (document.layers)
		document.layers[menu].visibility = "hide";
	else
		document.all[menu].style.visibility = "hidden";
}

function openMenu(menu)
{
	if (!oldMenu)
		oldMenu = memOldMenu;

	if (oldMenu != menu)
	{
		showLayer(menu);
		oldMenu = menu;
	}
	else
		oldMenu = "";
}

function checkMenu(menu)
{
	if (oldMenu && oldMenu != menu)
	{
		hideLayer(oldMenu);
		showLayer(menu);
		oldMenu = menu;
	}
}

function exitMenu()
{
	if(oldMenu)
		hideLayer(oldMenu);

	memOldMenu = oldMenu;
	oldMenu = "";
}