if (navigator.platform == "Win32" && navigator.appName == "Microsoft Internet Explorer" && window.attachEvent) {
	window.attachEvent("onload", alphaBackgrounds);
}

function alphaBackgrounds(){
	var rslt = navigator.appVersion.match(/MSIE (\d+\.\d+)/, '');
	var itsAllGood = (rslt != null && Number(rslt[1]) >= 5.5);
	for (i=0; i<document.all.length; i++){
		var bg = document.all[i].currentStyle.backgroundImage;
		if (itsAllGood && bg){
			if (bg.match(/\.png/i) != null){
				var mypng = bg.substring(5,bg.length-2);
				document.all[i].style.filter = "progid:DXImageTransform.Microsoft.AlphaImageLoader(src='"+mypng+"', sizingMethod='scale')";
				document.all[i].style.backgroundImage = "url('http://www.washingtonhistoryonline.org/treatytrail/images/spacer.gif')";
			}
		}
	}
}

// Correctly handle PNG transparency in Win IE 5.5 or higher.
// http://homepage.ntlworld.com/bobosola. Updated 02-March-2004
function correctPNG() 
{
  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
    }
  }
}
if (window.attachEvent) {
	window.attachEvent("onload", correctPNG);
}