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
}