var re = /(?:After|Before)EventListener/;
  currentEvents = {};
  opera.addEventListener('BeforeEventListener', function(e) {
    if (!re.test(e.event.type)) {
      currentEvents[e.event.type] = new Date();
    }
  },false);
  opera.addEventListener('AfterEventListener', function(e) {
    var type = e.event.type, time;
    if (!re.test(type) && (time = currentEvents[type])) {
      time = new Date() - time;
      if (time > 1000)
        opera.postError(type + ': ' + time + 'ms');
        currentEvents[type] = undefined;
    }
  }, false);