function toggleDiv()
{
  Element.toggle('mytree');
  Element.toggle('expanded');
  Element.toggle('collapsed');
  return false;
}
function showDrag()
{
  var drag_images = $$('img.drag_image');
  drag_images.all(function(value,index){return value.style.display='inline';});
  Element.toggle('done');
  Element.toggle('reorder');
  return false;
}
function hideDrag()
{
  var drag_images = $$('img.drag_image');
  drag_images.all(function(value,index){return value.style.display='none';});
  Element.toggle('done');
  Element.toggle('reorder');
  return false;
}

function toggleMyTree(id)
  {
  Element.toggle(id+'collapsed');
  Element.toggle(id+'expanded');
  Element.toggle(id+'children');
  return false;
  }
  function toggleBackground(el)
  {
  // using collection proxies to change the background
  var highlighted_el = $$("span.highlighted");
  highlighted_el.all(function(value,index){return value.className='normal'});

  el.className='highlighted';
  selected_el = el;
  return false;
  }
  function openMyTree(id)
  {
  Element.hide(id+'collapsed');
  Element.show(id+'expanded');
  Element.show(id+'children');
  return false;
  }