setTimeout in firefox modules.js

function setTimeout(callback, ms) {
  var _timer = Cc['@mozilla.org/timer;1']
                 .createInstance(Ci.nsITimer);
  _timer.initWithCallback({notify: callback}, ms, Ci.nsITimer.TYPE_ONE_SHOT);
  return _timer;
}

function clearTimeout(timer) {
  timer.cancel();
}