getAbsolutePos = function (el) {
  var SL = 0, ST = 0;
  if (el.scrollLeft)
    SL = el.scrollLeft;
  if (el.scrollTop)
    ST = el.scrollTop;
  var r = { x: el.offsetLeft - SL, y: el.offsetTop - ST };
  if (el.offsetParent) {
    var tmp = this.getAbsolutePos(el.offsetParent);
    r.x += tmp.x;
    r.y += tmp.y;
  }
  return r;
}  

function position(id) {
  var menuitem = document.getElementById('menuitem_' + id);
  var submenuitem = document.getElementById('submenuitem_' + id);

  var pos = getAbsolutePos(menuitem);

  submenuitem.style.left = pos.x + 'px';
}

function mouseover(id) {
  var element = document.getElementById('submenuitem_' + id);
  element.style.display = 'inline';

  var elem = document.getElementById('menuitem_' + id);
  if (elem.className == elem.className.replace(" mo", "")) {
    elem.className = elem.className + " mo";
  }
}

function mouseout(id) {
  var element = document.getElementById('submenuitem_' + id);
  element.style.display = 'none';

  var elem = document.getElementById('menuitem_' + id);
  elem.className = elem.className.replace(" mo", "");
}