Screen对象

document.write("Screen-"+screen.width+"Screen-height:"+screen.height);
document.write("<br/>Screen-"+screen.availWidth+"Screen-height:"+screen.availHeight);
document.write("<br/>window-"+window.innerWidth +"window-height:"+window.innerHeight);

　　Screen对象为整个显示屏的大小

      window对象为浏览器的大小