为什么只显示三行呀，我输出的明明是四行
<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
</head>
<body>
<script type="text/javascript">
document.write(window.innerHeight+"<br/>");
document.write(window.innerHeight+"<br/");
var w = document.documentElement.clientWidth || document.body.clientWidth;
var h= document.documentElement.clientHeight || document.body.clientHeight;
document.write(w + "<br/>" + h);
</script>
</body>
</html>
