var pageWidth = window.innerWidth;
var pageHeight = window.innerHeight;

if (typeof pageWidth != "number") {
    //在標準模式下面
    if (document.compatMode == "CSS1Compat" ) {
        pageWidth = document.documentElement.clientWidth;
        pageHeight = document.documentElement.clientHeight;
    } else {
        pageWidth = document.body.clientWidth;
        pageHeight = window.body.clientHeight;
    }
}
$('body').height(pageHeight);