获取当前scrollTop和scrollLeft，兼容XHTML

// JavaScript Document
/*  用法与测试:
    var myScroll = getScroll();
    alert("myScroll.scrollTop:" + myScroll.scrollTop);
    alert("myScroll.scrollLeft:" + myScroll.scrollLeft);
*/
function getScroll(){
        var scrollTop,scrollLeft;
        scrollTop = (document.body.scrollTop > document.documentElement.scrollTop) ? document.body.scrollTop : document.documentElement.scrollTop;//兼容浏览器
        
        if(isNaN(scrollTop) || scrollTop < 0){ scrollTop = 0;};//如果获取到非数字或者是小于0，那么等于0
        
        scrollLeft = (document.body.scrollLeft > document.documentElement.scrollLeft) ? document.body.scrollTop : document.documentElement.scrollLeft;
        
        if(isNaN(scrollLeft) || scrollLeft < 0){ scrollLeft = 0;};
        
        return{scrollTop:scrollTop,scrollLeft:scrollLeft};