function FindXY(id) { // Determine topleft X, Y coord of an element
  var obj = this.document.getElementById(id);
  var curleft = 0;
  var curtop = 0;
  if (obj.offsetParent) {
    do {
      curleft += obj.offsetLeft;
      curtop += obj.offsetTop;
    } while (obj = obj.offsetParent);
    return [curleft, curtop];
  } else {
    do {
      curleft += obj.clientLeft;
      curtop += obj.clientTop;
    } while (obj = obj.offsetParent);
    return [curleft, curtop];
  };
};