How do I create a custom event class in Javascript?

Question

How do I create a custom event class similar to ActionScript? What I mean by that is a class that I can use to fire off my own events, send the necessary data.

I don't wanna use third-party libraries like YUI or jQuery to do it. My goal is to be able to send a event that looks like this.

document.addEventListener("customEvent", eventHandler, false);

function eventHandler(e){
    alert(e.para1);
}

document.dispatchEvent(new CustomEvent("customEvent", para1, para2));

Please no third-party library solutions.

Answer 1

A method that worked for me was to call document.createEvent(), init it and dispatch it with window.dispatchEvent().

  var event = document.createEvent("Event");
  event.initEvent("customEvent", true, true);
  event.customData = getYourCustomData();
  window.dispatchEvent(event);