Find Obj Position with JavaScript

function findPosX(obj) {
  var curleft = 0;
    if (obj.offsetParent) {
      while (obj.offsetParent) {
        curleft += obj.offsetLeft - ((isOpera) ? 0 : obj.scrollLeft);
        obj = obj.offsetParent;
      }
      // IE offsetParent does not include the top-level
      if (isIE && obj.parentElement){
        curleft += obj.offsetLeft - obj.scrollLeft;
      }
    } 
    else if (obj.x) {
      curleft += obj.x;
    }
  return curleft;
}