关于图片上加浮动标签a的问题

代码如下：
HTML code：

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="textml; charset=utf-8" />
<title>无标题文档</title>
<style type="text/css">
.box{ width:500px; height:300px; border:5px solid #00F;position:relative;}
.left,.right{display:block;top:0;width:50px; height:300px;position:absolute;
}
.left span,.right span{position:relative;}
.left{left:0;}
.right{right:0;}
.right{ float:right;}
</style>
<SCRIPT type=text/javascript src="http://d.lanrentuku.com/down/js/xiangce-848/js/jquery.js"></SCRIPT>
<script type="text/javascript">
    $(function(){
                   $(".left,.right").mouseover(function(){
                                             $(this).html("<span><img src='images/leftbig.png'></span>")
                                              }).mouseout(function(){
                                                  $(this).html("")
                                            })
               })
</script>
</head>
<body>
<div>
<div><img src="/uploads/201411/f94feeae3b52fd2bb9051d9e0bb70da21.jpg" width="500" height="300" /></div>
    <a href="#"></a>
    <a  href="#"></a>
</div>
</body>

问题：鼠标移运到a标签，给a标签添加一个箭头图片。在谷歌下面是正常的，但是ie下面就没反应了，应该如何来修改？
修改后的准确代码如下：
CCS code:

<style type="text/css">
.box{ width:500px; height:300px; border:5px solid #00F;position:relative;}
.left,.right{display:block;top:0;width:50px; height:300px;position:absolute; z-index:99; background:url(一张透明图片.png) repeat;}
.left span,.right span,.img{position:relative;}
.img{ z-index:10;}
.left{left:0;}
a.left:hover{background:url(/uploads/201411/f94feeae3b52fd2bb9051d9e0bb70da21.jpg) no-repeat center center;}
.right{right:0; }
a.right:hover{background:url(/uploads/201411/f94feeae3b52fd2bb9051d9e0bb70da21.jpg) no-repeat center center;}
</style>

HTML code:

<div><img src="/uploads/201411/f94feeae3b52fd2bb9051d9e0bb70da21.jpg" width="500" height="300" /></div>
    <a href="#"></a>
    <a  href="#"></a>
</div>

编程技巧