function showHint(id) {
  var img = document.all["img"];
  var a = document.all["area" + id];
  var hint = document.all["hint" + id];
  var x = getAbsoluteLeftOffset(img) + a.offsetLeft;
  var y = getAbsoluteTopOffset(img) + a.offsetTop - 20;
  hint.style.left = x;
  hint.style.top = y;
  hint.style.display = "block"
}

function hideHint(id) {
  var hint = document.all["hint" + id];
  hint.style.display = "none"
}

function getAbsoluteLeftOffset(elt) {
  var x = elt.offsetLeft;
  var obj = elt.offsetParent;
  while (obj != null) {
      x = x + obj.offsetLeft + obj.clientLeft;
      obj = obj.offsetParent
  }
  return x;
}

function getAbsoluteTopOffset(elt) {
  var y = elt.offsetTop;
  var obj = elt.offsetParent;
  while (obj != null) {
      y = y + obj.offsetTop + obj.clientTop;
      obj = obj.offsetParent
  }
  return y;
}