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

function enableAlphaImages(){
var rslt = navigator.appVersion.match(/MSIE (\d+\.\d+)/, '');
var itsAllGood = (rslt != null && Number(rslt[1]) >= 5.5);
if (itsAllGood) {
for (var i=0; i<document.all.length; i++){
var obj = document.all[i];
var bg = obj.currentStyle.backgroundImage;
var img = document.images[i];
if (bg && bg.match(/\.png/i) != null) {
var img = bg.substring(5,bg.length-2);
var offset = obj.style["background-position"];
obj.style.filter =
"progid:DXImageTransform.Microsoft.AlphaImageLoader(src='"+img+"', sizingMethod='crop')";
obj.style.backgroundImage = "url('http://www.zhangxinxu.com/study/image/pixel.gif')";//替换透明PNG的图片
obj.style["background-position"] = offset; // reapply
} else if (img && img.src.match(/\.png$/i) != null) {
var src = img.src;
img.style.width = img.width + "px";
img.style.height = img.height + "px";
img.style.filter =
"progid:DXImageTransform.Microsoft.AlphaImageLoader(src='"+src+"', sizingMethod='crop')"
img.src = "";//替换透明PNG的图片
}
}
}
}



function correctPNG() // correctly handle PNG transparency in Win IE 5.5 & 6 & 7 & 8 . 
{ 
     var arVersion = navigator.appVersion.split("MSIE") 
     var version = parseFloat(arVersion[1]) 
     if ((version >= 5.5) && (document.body.filters)) 
     { 
       for(var j=0; j<document.images.length; j++) 
       { 
           var img = document.images[j] 
           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 
             j = j-1 
           } 
       } 
     }     
} 
window.attachEvent("onload", correctPNG);