document.body.clientWidth ==> BODY对象宽度
document.body.clientHeight ==> BODY对象高度
document.documentElement.clientWidth ==> 可见区域宽度
document.documentElement.clientHeight ==> 可见区域高度
注意开头<!DOCTYPE ..>的声明，没有该声明时，document.documentElement.clientHeight 始终在Chrome中为1016 px
测试代码：
<!DOCTYPE html > <head> <title> New Document </title> <script language="JavaScript"> function a(){ document.getElementById("bodyheight").innerText = document.body.clientHeight; document.getElementById("documentheight").innerText = document.documentElement.clientHeight; } </script> </head> <body style= "height: 1000px;"> <p> <a href="javascript:a()">click here</a> <br/> document.body.clientHeight = <span id="bodyheight"></span> px <br/> document.documentElement.clientHeight = <span id="documentheight"></span> px </p> </body> </html>
[No000068]document.body.clientHeight 和 document.documentElement.clientHeight 的区别
原文：http://www.cnblogs.com/Chary/p/No000068.html