ul 居中
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
??????? "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
??? <style type="text/css">
??????? #ul1{width: 300px;height: 300px;border: 1px solid #000000; margin: 10px auto;}
??? </style>
??? <meta http-equiv="Content-Type" content="text/html; charset=gb2312"/>
??? <title></title>
</head>
<body>
<ul id="ul1">
</ul>
</body>
</html>
