解决IE浏览器文字上面放无内容的元素选不中的方法

<div class="md1">
    <p><i>sdgsgereryeryery</i></p>
    <label class="rank r1"></label>
    <label class="rank r2"></label>
    <label class="rank r3"></label>
    <label class="rank r4"></label>
</div>

.md1{position:relative;}
.md1 .rank{cursor:pointer;position:absolute;width:16px;height:15px;top:3px;}
.md1 .rank.r1{left:0px;border:1px solid red;}
.md1 .rank.r2{left:16px;border:1px solid black;}
.md1 .rank.r3{left:32px;border:1px solid blue;}
.md1 .rank.r4{left:48px;border:1px solid green;}

上面的代码在ie中无法点击到label，解决的办法是给label填充透明的背景色

.md1 .rank{cursor:pointer;position:absolute;width:16px;height:15px;top:3px;background:#ffffff;opacity:0;filter: progid:DXImageTransform.Microsoft.Alpha(opacity=0);}