// taken from http://www.netlobo.com/div_hiding.html May 2007
	function toggleLayer( whichLayer, txt )
{
  var elem, vis, text;
  if( document.getElementById ) // this is the way the standards work
    elem = document.getElementById( whichLayer );
  else if( document.all ) // this is the way old msie versions work
      elem = document.all[whichLayer];
  else if( document.layers ) // this is the way nn4 works
    elem = document.layers[whichLayer];
  vis = elem.style;
  // if the style.display value is blank we try to figure it out here
  if(vis.display==''&&elem.offsetWidth!=undefined&&elem.offsetHeight!=undefined)
	  {vis.display = (elem.offsetWidth!=0&&elem.offsetHeight!=0)?'block':'none';}
  if(vis.display==''||vis.display=='block')
  {
	  vis.display = 'none';
	  document.getElementById(txt).innerHTML = '[+]';
  }
  else{
  vis.display = 'block';
  document.getElementById(txt).innerHTML = '[-]';
  }
}