Correct the transparacy of PNG in IE5 and IE6

<!-- Convertir todos los PNG en transparentes para IE, versiones anteriores a la 7-->
<!--[if lt IE 7]>
<script language="JavaScript">
function correctPNG() // correctly handle PNG transparency in Win IE 5.5 & 6.
{
  var arVersion = navigator.appVersion.split("MSIE")
  var version = parseFloat(arVersion[1])
  if ((version >= 5.5) && (document.body.filters))
  {
     for(var i=0; i<document.images.length; i++)
     {
        var img = document.images[i]
        var imgName = img.src.toUpperCase()
        if (imgName.substring(imgName.length-3, imgName.length) == "PNG")
        {
           var imgID = (img.id) ? "id='" + img.id + "' " : ""
           var imgClass = (img.className) ? "class='" + img.className + "' " : ""
           var imgTitle = (img.title) ? "title='" + img.title + "' " : "title='" + img.alt + "' "
           var imgStyle = "display:inline-block;" + img.style.cssText
           if (img.align == "left") imgStyle = "float:left;" + imgStyle
           if (img.align == "right") imgStyle = "float:right;" + imgStyle
           if (img.parentElement.href) imgStyle = "cursor:hand;" + imgStyle
           var strNewHTML = "<span " + imgID + imgClass + imgTitle
           + " style=\"" + "width:" + img.width + "px; height:" + img.height + "px;" + imgStyle + ";"
           + "filter:progid:DXImageTransform.Microsoft.AlphaImageLoader"
           + "(src=\'" + img.src + "\', sizingMethod='scale');\"></span>"
           img.outerHTML = strNewHTML
           i = i-1
        }
     }
  }
}
window.attachEvent("onload", correctPNG);
</script>
<![endif]-->