javascript 获取当前页面可视高度和宽度的函数

    function getPageSize(){
        var xScroll,yScroll;
        if (window.innerHeight && window.scrollMaxY){
            xScroll = window.innerWidth + window.scrollMaxX;
            yScroll = window.innerHeight + window.scrollMaxY;
        }
        else if (document.body.scrollHeight > document.body.offsetHeight){ 
        // all but Explorer Mac
            xScroll = document.body.scrollWidth;
            yScroll = document.body.scrollHeight;
        }else{// Explorer Mac...would also work in Explorer 6 Strict, Mozilla and Safari
            xScroll = document.body.offsetWidth;
            yScroll = document.body.offsetHeight;
        }

        var windowWidth, windowHeight;
        if (self.innerHeight){ // all except Explorer
            windowWidth = self.innerWidth;
            windowHeight = self.innerHeight;
        }
        else if (document.documentElement && document.documentElement.clientHeight){
        // Explorer 6 Strict Mode
            windowWidth = document.documentElement.clientWidth;
            windowHeight = document.documentElement.clientHeight;
        }
        else if (document.body){// other Explorers
            windowWidth = document.body.clientWidth;
            windowHeight = document.body.clientHeight;
        }

        // for small pages with total height less then height of the viewport
        var pageWidth,pageHeight;
        if(yScroll < windowHeight){
            pageHeight = windowHeight;
        }else{
            pageHeight = yScroll;
        }

        if(xScroll < windowWidth){
            pageWidth = windowWidth;
        }else{
            pageWidth = xScroll;
        }
        return {
            "pageWidth":pageWidth,
            "pageHeight":pageHeight
        }
    }
//alert(getPageSize().pageHeight)

javascript 获取当前页面可视高度和宽度的函数