Custom event acomplished in Class

The following two code samples were given to me at a job interview and I couldn't manage to make it work:

//CODE1:
var e = new Event();

e.on('myevent', function (a, b) {
    console.log(a + ' ' + b);
});

e.trigger('myevent', ['Hello', 'world']);


//CODE2:  
e.on('hello', function() {
    console.log('Hello');
    this.trigger('world');
}).on('world', function() {
    console.log('World');
}).trigger('hello');

So the given two codes can't be modified, the Class called Event() should work so both the two code samples would output "Hello world". Now, I'm not asking for a complete answer. I'm not that good at Classes and Custom events in Javascript. I know the basics, but it's not really in my hands yet, if You know what I mean. I've been searching for tutorials, but I need someone "smarter" to tell me where should I start, providing maybe some links for good tutorials for my problem.

Thanks!

Demo http://jsfiddle.net/uAQn9/

Code:

function Event() {

}

Event.prototype = {

  trigger:function(eventName, arParam) {
    $(window).trigger(eventName, arParam);
  },

  on: function(eventName, cb) {
    var event = this;
    $(window).on(eventName, function(e) {
      var args = Array.prototype.slice.call(arguments);
      cb.apply(event, args.slice(1));
    });
    return this;
  }
}

//CODE1:
var e = new Event();

e.on('myevent', function (a, b) {
    console.log(a + ' ' + b);
});

e.trigger('myevent', ['Hello', 'world']);


//CODE2:  
e.on('hello', function() {
    console.log('Hello');
    this.trigger('world');
}).on('world', function() {
    console.log('World');
}).trigger('hello');