js 获取元素标签的绝对定位位置

//获取某个html元素的定位        function GetPos(obj) {            var pos = new Object();            pos.x = obj.offsetLeft;            pos.y = obj.offsetTop;            while (obj = obj.offsetParent) {                pos.x += obj.offsetLeft;                pos.y += obj.offsetTop;            }            return pos;        };

//判断滚动条到底部的JS代码$(window).scroll(function() {　　   var scrollTop = $(this).scrollTop();　　   var scrollHeight = $(document).height();　　   var windowHeight = $(this).height();　　   if (scrollTop + windowHeight == scrollHeight) {　　　　       alert("you are in the bottom");　　   }<p>});</p>