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;
	}