效果图：
html：

dd_belatedpng实现ie6下的透明背景1、通过公共类pngfixwindow.onload = function () {dd_belatedpng.fix(.pngfix,.pngfix:hover);}
2、直接用选择器：类名，id，标签实现dd_belatedpng.fix(.imgpng,img);

css:

dd_belatedpng.js:
var dd_belatedpng={ns:dd_belatedpng,imgsize:{},delay:10,nodesfixed:0,createvmlnamespace:function(){if(document.namespaces&&!document.namespaces[this.ns]){document.namespaces.add(this.ns,urn:schemas-microsoft-com:vml)}},createvmlstylesheet:function(){var b,a;b=document.createelement(style);b.setattribute(media,screen);document.documentelement.firstchild.insertbefore(b,document.documentelement.firstchild.firstchild);if(b.stylesheet){b=b.stylesheet;b.addrule(this.ns+\\:*,{behavior:url(#default#vml)});b.addrule(this.ns+\\:shape,position:absolute;);b.addrule(img.+this.ns+_sizefinder,behavior:none; border:none; position:absolute; z-index:-1; top:-10000px; visibility:hidden;);this.screenstylesheet=b;a=document.createelement(style);a.setattribute(media,print);document.documentelement.firstchild.insertbefore(a,document.documentelement.firstchild.firstchild);a=a.stylesheet;a.addrule(this.ns+\\:*,{display: none !important;});a.addrule(img.+this.ns+_sizefinder,{display: none !important;})}},readpropertychange:function(){var b,c,a;b=event.srcelement;if(!b.vmlinitiated){return}if(event.propertyname.search(background)!=-1||event.propertyname.search(border)!=-1){dd_belatedpng.applyvml(b)}if(event.propertyname==style.display){c=(b.currentstyle.display==none)?none:block;for(a in b.vml){if(b.vml.hasownproperty(a)){b.vml[a].shape.style.display=c}}}if(event.propertyname.search(filter)!=-1){dd_belatedpng.vmlopacity(b)}},vmlopacity:function(b){if(b.currentstyle.filter.search(lpha)!=-1){var a=b.currentstyle.filter;a=parseint(a.substring(a.lastindexof(=)+1,a.lastindexof())),10)/100;b.vml.color.shape.style.filter=b.currentstyle.filter;b.vml.image.fill.opacity=a}},handlepseudohover:function(a){settimeout(function(){dd_belatedpng.applyvml(a)},1)},fix:function(a){if(this.screenstylesheet){var c,b;c=a.split(,);for(b=0;bn.h){i.b=n.h}d.vml.image.shape.style.clip=rect(+i.t+px +(i.r+a)+px +i.b+px +(i.l+a)+px)}else{d.vml.image.shape.style.clip=rect(+f.t+px +f.r+px +f.b+px +f.l+px)}},figurepercentage:function(d,c,f,a){var b,e;e=true;b=(f==x);switch(a){caseleft:casetop:d[f]=0;break;casecenter:d[f]=0.5;break;caseright:casebottom:d[f]=1;break;default:if(a.search(%)!=-1){d[f]=parseint(a,10)/100}else{e=false}}d[f]=math.ceil(e?((c[b?w:h]*d[f])-(c[b?w:h]*d[f])):parseint(a,10));if(d[f]%2===0){d[f]++}return d[f]},fixpng:function(c){c.style.behavior=none;var g,b,f,a,d;if(c.nodename==body||c.nodename==td||c.nodename==tr){return}c.isimg=false;if(c.nodename==img){if(c.src.tolowercase().search(/\.png$/)!=-1){c.isimg=true;c.style.visibility=hidden}else{return}}else{if(c.currentstyle.backgroundimage.tolowercase().search(.png)==-1){return}}g=dd_belatedpng;c.vml={color:{},image:{}};b={shape:{},fill:{}};for(a in c.vml){if(c.vml.hasownproperty(a)){for(d in b){if(b.hasownproperty(d)){f=g.ns+:+d;c.vml[a][d]=document.createelement(f)}}c.vml[a].shape.stroked=false;c.vml[a].shape.appendchild(c.vml[a].fill);c.parentnode.insertbefore(c.vml[a].shape,c)}}c.vml.image.shape.fillcolor=none;c.vml.image.fill.type=tile;c.vml.color.fill.on=false;g.attachhandlers(c);g.givelayout(c);g.givelayout(c.offsetparent);c.vmlinitiated=true;g.applyvml(c)}};try{document.execcommand(backgroundimagecache,false,true)}catch(r){}dd_belatedpng.createvmlnamespace();dd_belatedpng.createvmlstylesheet();