美化type="file"

<div class="fileInput left">
  <input type="file" name="upfile" id="upfile" class="upfile" onchange="document.getElementById('upfileResult').innerHTML=this.value"/>
    <input class="upFileBtn" type="button" value="上传图片" onclick="document.getElementById('upfile').click()" />
</div>
<span class="tip left" id="upfileResult">图片大小不超过2M,大小90*90,支持jpg、png、bmp等格式。</span>

.fileInput{width:102px;height:34px; background:url(http://images.cnblogs.com/cnblogs_com/dreamback/upFileBtn.png);overflow:hidden;position:relative;}
.upfile{position:absolute;top:-100px;}
.upFileBtn{width:102px;height:34px;opacity:0;filter:alpha(opacity=0);cursor:pointer;}

来源：http://www.cnblogs.com/dreamback/archive/2011/10/12/2208557.html