// from http://www.dustindiaz.com/dhtml-expand-and-collapse-div-menu/

function toggleDiv(obj)
{
  var el = document.getElementById(obj);

  if ( el.style.display != 'none' )
  {
    el.style.display = 'none';
  }
  else
  {
    el.style.display = '';
  }
}