Browser Side Event Emitter

gistfile1.js

/**
 * Small EventEmitter implementation borowed from MicroEvent.js
 *
 * MicroEvent.js: https://github.com/jeromeetienne/microevent.js
 */
var Emitter = function(){};
Emitter.prototype	= {
    on: function(event, fct){
        this._events = this._events || {};
        this._events[event] = this._events[event]	|| [];
        this._events[event].push(fct);
    },
    removeListener: function(event, fct){
        this._events = this._events || {};
        if( event in this._events === false  )	return;
        this._events[event].splice(this._events[event].indexOf(fct), 1);
    },
    emit: function(event /* , args... */){
        this._events = this._events || {};
        if( event in this._events === false  )	return;
        for(var i = 0; i < this._events[event].length; i++){
            this._events[event][i].apply(this, Array.prototype.slice.call(arguments, 1));
        }
    }
};

/**
 * Enable will delegate all Emitter function in the destination object
 *
 * Emitter.enable(Foobar) will make Foobar able to act as an EventEmitter
 */
Emitter.enable = function(destObject){
    var props = ['on', 'removeListener', 'emit'];
    for(var i = 0; i < props.length; i ++){
        destObject.prototype[props[i]]	= Emitter.prototype[props[i]];
    }
};