css实现图片水平垂直居中

<!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="text/html; charset=utf-8" />
<title>图片水平垂直居中</title>
<style type="text/css">

 ul{ list-style:none outside none;}
.sjk li{float:left; margin-right:13px;} 
.sjk li div{display:table-cell; width:144px; height:144px; border:1px solid #beceeb; font-size:126px; text-align:center; vertical-align:middle;}
.sjk li div img{vertical-align:middle;}

</style>
</head>
<body>

<ul class="sjk fix">
         <li><div><img src="http://image.zhangxinxu.com/image/study/s/s128/mm1.jpg" /></div> </li>
        <li><div><img src="http://image.zhangxinxu.com/image/study/s/s128/mm1.jpg" /></div> </li>
        <li><div><img src="http://image.zhangxinxu.com/image/study/s/s128/mm1.jpg" /></div> </li>
</ul>

</body>
</html>
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