if (document.all)
  document.getElementById = document.all;
var dhtml = (document.getElementById || document.all) && navigator.userAgent.indexOf('Opera') == -1 ? true : false;
var i, displayed = new Array('', true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true);

if (dhtml) {
  var folder_closed = document.createElement('img');
  folder_closed.setAttribute('src','../images/tree/folder-closed.gif');
  var plus_cross = document.createElement('img');
  plus_cross.setAttribute('src','../images/tree/plus-cross.gif');
  var plus_corner = document.createElement('img');
  plus_corner.setAttribute('src','../images/tree/plus-corner.gif');
  var folder_open = document.createElement('img');
  folder_open.setAttribute('src','../images/tree/folder-open.gif');
  var minus_cross = document.createElement('img');
  minus_cross.setAttribute('src','../images/tree/minus-cross.gif');
  var minus_corner = document.createElement('img');
  minus_corner.setAttribute('src','../images/tree/minus-corner.gif');
  document.write('<style type="text/css">#menuHolder{visibility: hidden;}' + (document.all && (!document.getElementById || !document.getElementsByTagName) ? '#menuHolder img {vertical-align: text-top;}' : '') + '</style>');
}

function loadMenu()
{
  for (i = 1; i <= 20; i++)
    menuClick(i, i == 20 ? true : false);
  document.getElementById('menuHolder').style.visibility = 'visible';
}

function menuClick(id, last)
{
  if (dhtml) {
    document.getElementById('menu' + id).style.display = (displayed[id] ? 'none' : 'block');
    if (!last)
      document.getElementById('marker' + id).setAttribute('src', displayed[id] ? plus_cross.getAttribute('src') : minus_cross.getAttribute('src'));
    else
      document.getElementById('marker' + id).setAttribute('src', displayed[id] ? plus_corner.getAttribute('src') : minus_corner.getAttribute('src'));
    document.getElementById('folder' + id).setAttribute('src', displayed[id] ? folder_closed.getAttribute('src') : folder_open.getAttribute('src'));
    displayed[id] = (displayed[id] == true ? false : true);
  }
}