js实现IE6下png背景透明，超简单，超牛！

var bgsleight = function() { function addLoadEvent(func) { var oldonload = window.onload; if (typeof window.onload != 'function') { window.onload = func; } else { window.onload = function() { if (oldonload) { oldonload(); } func(); } } } function fnLoadPngs() { var rslt = navigator.appVersion.match(/MSIE (\d+\.\d+)/, ''); var itsAllGood = (rslt != null && Number(rslt[1]) >= 5.5); for (var i = document.all.length - 1, obj = null; (obj = document.all[i]); i--) { if (itsAllGood && obj.currentStyle.backgroundImage.match(/\.png/i) != null) { fnFixPng(obj); obj.attachEvent("onpropertychange", fnPropertyChanged); } } } function fnPropertyChanged() { if (window.event.propertyName == "style.backgroundImage") { var el = window.event.srcElement; if (!el.currentStyle.backgroundImage.match(/x\.gif/i)) { var bg = el.currentStyle.backgroundImage; var src = bg.substring(5,bg.length-2); el.filters.item(0).src = src; el.style.backgroundImage = "url(x.gif)"; } } } function fnFixPng(obj) { var bg = obj.currentStyle.backgroundImage; var src = bg.substring(5,bg.length-2); obj.style.filter = "progid:DXImageTransform.Microsoft.AlphaImageLoader(src='" + src + "', sizingMethod='scale')"; obj.style.backgroundImage = "url(x.gif)"; } return { init: function() { if (navigator.platform == "Win32" && navigator.appName == "Microsoft Internet Explorer" && window.attachEvent) { addLoadEvent(fnLoadPngs); } } } }(); bgsleight.init();