function getNextSiblingTag(obj)
{
	var nextObj = obj.nextSibling;
	if (!nextObj) return null;
	
	while (nextObj.nodeType != 1)
	{
		nextObj = nextObj.nextSibling;
		if (nextObj == null) return null;
		if (nextObj == obj.lastChild) return null;
	}
	return nextObj;
}

function openSubMenu(obj)
{
	var subMenu = null;
	var subMenuDisplay = "none";
	
	subMenu = getNextSiblingTag(obj);
	if (subMenu == null) return;
	
	subMenuDisplay = (subMenu.style.display == "block") ? "none" : "block";
	
	while (subMenu != null)
	{
		subMenu.style.display = subMenuDisplay;
		subMenu = getNextSiblingTag(subMenu);
	}
}