อ่านตำแหน่งของ element

function posLeft(eElement)
{
  var nLeftPos = eElement.offsetLeft;
  var eParElement = eElement.offsetParent;
  while (eParElement != null)
  {
    nLeftPos += eParElement.offsetLeft;
    eParElement = eParElement.offsetParent;
  }
  return nLeftPos;
}

function posTop(eElement)
{
  var nTopPos = eElement.offsetTop;
  var eParElement = eElement.offsetParent;
  while (eParElement != null)
  {
    nTopPos += eParElement.offsetTop;
    eParElement = eParElement.offsetParent;
  }
  return nTopPos;
}