function showSubmenu(obj)
{
	obj                   = obj.parentNode;										// The link is on the A-tag, so the LI is the parent
	var sub               = obj.getElementsByTagName('UL');						// Get the UL of the submenu
	var overlay           = document.getElementById('overlay');					// Get the overlay
	var body              = document.getElementsByTagName('BODY')[0];			// Get the body
	
	// Get al LI's on the same level as "obj"
	var parent            = obj.parentNode;
	var children          = parent.childNodes;
	
	for(var i = 0; i < children.length; i++)
	{
		var child = children[i];
		
		if(child.nodeName == 'LI')
		{
			var menu = child.getElementsByTagName('UL')
			
			if(menu.length)
			{
				menu[0].style.display = 'none';
			}
		}
	}
	
	if(sub.length)
	{
		sub[0].style.display     = 'block';
	}
	
	overlay.style.display = 'block';
	overlay.style.height  = body.clientHeight + 'px';
}

function closeOverlay(obj)
{
	// Hide the overlay
	obj.style.display = 'none';
	
	// Close the submenu
	var udm           = document.getElementById('udm');
	var uls           = udm.getElementsByTagName('UL');
	
	for(var i = 0; i < uls.length; i++)
	{
		uls[i].style.display = 'none';
	}
}