js获取页面实际大小-ie-firefox

//获取页面实际大小
function getPageSize(){
var xScroll,yScroll;
if (window.innerHeight && window.scrollMaxY){
xScroll = document.body.scrollWidth;
yScroll = window.innerHeight + window.scrollMaxY;
} else if (document.body.scrollHeight > document.body.offsetHeight){
sScroll = document.body.scrollWidth;
yScroll = document.body.scrollHeight;
} else {
xScroll = document.body.offsetWidth;
yScroll = document.body.offsetHeight;
}
var windowWidth,windowHeight;
//var pageHeight,pageWidth;
if (self.innerHeight) {
windowWidth = self.innerWidth;
windowHeight = self.innerHeight;
} else if (document.documentElement &&  document.documentElement.clientHeight) {
windowWidth = document.documentElement.clientWidth;
windowHeight = document.documentElement.clientHeight;
} else if (document.body) {
windowWidth = document.body.clientWidth;
windowHeight = document.body.clientHeight;
}
var pageWidth,pageHeight
if(yScroll < windowHeight){
pageHeight = windowHeight;
} else {
pageHeight = yScroll;
}
if(xScroll < windowWidth) {
pageWidth = windowWidth;
} else {
pageWidth = xScroll;
}
arrayPageSize = new Array(pageWidth,pageHeight,windowWidth,windowHeight)
return arrayPageSize;
}