window.screen.availWidth 返回当前屏幕宽度(空白空间)
window.screen.availHeight 返回当前屏幕高度(空白空间) （1160像素，少了40像素？？？）
window.screen.width 返回当前屏幕宽度(分辨率值) $(window).width()为浏览器窗口的宽度
window.screen.height 返回当前屏幕高度(分辨率值)
window.document.body.offsetWidth; 返回当前网页宽度 （网页的宽度为1904，少了16像素????）
window.document.body.offsetHeight; 返回当前网页高度 （若网页中只有一个100像素高的div，此值就为100px）
1 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
2 <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
3 <head>
4 <meta http-equiv="Content-Type" content="text/html;charset=UTF-8">
5 <title>window.screen</title>
6 <script type="text/javascript" src='js/jquery.js'></script>
7 <script type="text/javascript">
8 $(function(){
9 console.log(window.screen.availWidth); //1920
10 console.log(window.screen.availHeight); //1160
11 console.log(window.screen.width); //1920
12 console.log(window.screen.height); //1200
13 console.log(window.document.body.offsetWidth); //1904
14 console.log(window.document.body.offsetHeight); //500
15 })
16 </script>
17 </head>
18 <body>
19 <div style='width:100px; height:500px;'></div>
20 </body>
21 </html>