var currentMenuItem

function toggleSubMenu(menuItemID)
{
	var menuItem = document.getElementById(menuItemID);
	var isTopLevelNav;
		
	menuItem.className = switchClassName(menuItem.className);	
	if(currentMenuItem!=null)
	{	
		if(currentMenuItem!=menuItem)
		{
			ensureMenuItemClosed(currentMenuItem);
		}
	}
	
	currentMenuItem = menuItem;	
}

function switchClassName(className)
{
	className = className.indexOf('Show')>-1?className.replace('Show','Hide'):className.replace('Hide','Show');
	return className;
}

function ensureMenuItemClosed(menuItem)
{
	if(menuItem.className.indexOf('Show')>-1)
	{
		menuItem.className = switchClassName(menuItem.className);
	}
}