载自 http://www.aa25.cn/div_css/875.shtml
?
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>如何让一个块级元素水平居中</title>
<style type="text/css">
#layout {
?background-color: #CCCCCC;
?height: 240px;
?width:80%;
?margin:0 auto;
}
</style>
</head>
<body>
<div id="layout">此处显示? id "layout" 的内容</div>
</body>
</html>
?
注意:以上必须加入 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
?声明，才可以居中