页面刷新， 定位， 动态下拉框

function getScrolling() {
            var x = 0; var y = 0;
            if (document.body && document.body.scrollLeft && !isNaN(document.body.scrollLeft)) {
                x = document.body.scrollLeft;
            } else if (window.pageXOffset && !isNaN(window.pageXOffset)) {
                x = window.pageXOffset;
            }
            if (document.body && document.body.scrollTop && !isNaN(document.body.scrollTop)) {
                y = document.body.scrollTop;
            } else if (window.pageYOffset && !isNaN(window.pageYOffset)) {
                y = window.pageYOffset;
            }
            return x + "," + y;
        }