记录一下获取浏览器可视区域的大小的js

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) {
            xScroll = document.body.scrollWidth;
            yScroll = document.body.scrollHeight;
        } else {
            xScroll = document.body.offsetWidth;
            yScroll = document.body.offsetHeight;
        }
        var windowWidth, windowHeight;
        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;
        }
        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;
    }