<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>b.html</title>
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="this is my page">
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<style type="text/css">
#d2 {
width:400px;
height:200px;
border:5px solid gray;
padding:5px;
}
</style>
<script>
window.onload=function(){
//2、使用嵌入、链入或引入样式表（非内联样式）
//ie：通过currentStyle
alert(document.getElementById('d2').currentStyle.width);//400px ie
//ff,safari,opera,chrome:通过window.getComputedStyle
var el=document.getElementById('d2');
alert(window.getComputedStyle(el,null).style.width);//400px safari,opera,chrome
}
</script>
</head>
<body>
<div id="d2"></div>
</body>
</html>