Sys.Application.add_load
(
  function() 
  {
    // fix png alpha on versions of IE prior to 7
    if(Sys.Browser.agent == Sys.Browser.InternetExplorer && Sys.Browser.version < 7) 
    {
      for (var i=0; i<document.images.length; i++)
      {
        var image = document.images.item(i);
        if (/fixie/.test(image.className))
        {
          image.style.filter = 'progid:DXImageTransform.Microsoft.AlphaImageLoader(src=' + image.src + ', sizingMethod="image")';
          image.src = image.src.replace(/[^\/]+\.png$/i,'blank.gif');
          image.className = image.className.replace(/fixie/, '');
        }
      }
    }
  }
);