javascript : find position

var findpos = function findPos(obj) {
   var curleft = curtop = 0;
   if (obj.offsetParent) {
      do {
      curleft += obj.offsetLeft;
      curtop += obj.offsetTop;
      } while (obj = obj.offsetParent);
      return [curleft,curtop];
   }
}


http://www.quirksmode.org/js/findpos.html