// 获取窗口宽度if (window.innerWidth)winWidth = window.innerWidth;else if ((document.body) && (document.body.clientWidth))winWidth = document.body.clientWidth;// 获取窗口高度if (window.innerHeight)winHeight = window.innerHeight;else if ((document.body) && (document.body.clientHeight))winHeight = document.body.clientHeight;// 通过深入 Document 内部对 body 进行检测，获取窗口大小if (document.documentElement && document.documentElement.clientHeight && document.documentElement.clientWidth){winHeight = document.documentElement.clientHeight;winWidth = document.documentElement.clientWidth;}原文：http://www.cnblogs.com/dy09/p/5126560.html