js 获取html控件的水平位置

	function getAbsoluteLeft(objId) {
		o = document.getElementById(objId);
		oLeft = o.offsetLeft;
		while(o.offsetParent!=null) { 
		oParent = o.offsetParent;   
		oLeft += oParent.offsetLeft;
		o = oParent;
		}
		return oLeft;
		}