为什么body那么另类？？
<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
</head>
<body>
<script type="text/javascript">
document.write("浏览器可视区域大小documentElement:"+document.documentElement.clientWidth +"+"+ document.documentElement.clientHeight+"<br/>");
document.write("浏览器可视区域大小body:"+document.body.clientWidth +"+"+ document.body.clientHeight+"<br/>");
document.write("浏览器可视区域大小inner:"+window.innerWidth +"+"+ window.innerHeight+"<br/>");
document.write("屏幕可用宽高"+screen.availWidth+"+"+screen.availHeight+"<br/>");
document.write("屏幕分辨宽高"+screen.width+"+"+screen.height);
</script>
</body>
</html>
