function expand_nav(link)
			{
				var ul = find_enclosing_ul(link)
				if (ul.style.display == 'none')
				{
					ul.style.display = 'block'
				}
				else
				{
					ul.style.display = 'none'
				}
				if (link.className == 'down')
				{
					link.className='down_open'
				}
				else
				{
					link.className='down'
				}
			}
			
			function find_enclosing_ul(link)
			{
				var search_node = link
				while (true)
				{
					var node = search_node.nextSibling
					if (node && node.nodeName == 'UL')
					{
						break
					}
					else
					{
						search_node = node
					}
				}
				return node	
			}