function getOffsetTop(elm) {
  var mOffsetTop = elm.offsetTop;
  var mOffsetParent = elm.offsetParent;
  while(mOffsetParent){
    mOffsetTop += mOffsetParent.offsetTop;
    mOffsetParent = mOffsetParent.offsetParent;
  }
  return mOffsetTop;
}

function getOffsetLeft(elm) {
  var mOffsetLeft = elm.offsetLeft;
  var mOffsetParent = elm.offsetParent;
  while(mOffsetParent){
    mOffsetLeft += mOffsetParent.offsetLeft;
    mOffsetParent = mOffsetParent.offsetParent;
  }
  return mOffsetLeft;
}