function setElementOpacity(elem, nOpacity)
{
  var opacityProp = getOpacityProperty();

  if (!elem || !opacityProp) return;
  
  if (opacityProp=="filter")
  {
    nOpacity *= 100;
	
    var oAlpha = elem.filters['DXImageTransform.Microsoft.alpha'] || elem.filters.alpha;
    if (oAlpha) oAlpha.opacity = nOpacity;
    else elem.style.filter += "progid:DXImageTransform.Microsoft.Alpha(opacity="+nOpacity+")";
  }
  else
    elem.style[opacityProp] = nOpacity;
}

function getOpacityProperty()
{
  if (typeof document.body.style.opacity == 'string')
    return 'opacity';
  else if (typeof document.body.style.MozOpacity == 'string')
    return 'MozOpacity';
  else if (typeof document.body.style.KhtmlOpacity == 'string')
    return 'KhtmlOpacity';
  else if (document.body.filters && navigator.appVersion.match(/MSIE ([\d.]+);/)[1]>=5.5)
    return 'filter';

  return false;
}