Pretty Small Custom EventDispatcher

Custom-EventDispatcher.js

var EventDispatcher= function() {
    this.events = {};
}

EventDispatcher.prototype.add = function(name, handler) {
    if(!(name in this.events)) {
        this.events[name] = [handler];
    } else {
        this.events[name].push(handler);
    }
}

EventDispatcher.prototype.dispatch = function(name,data) {
    if(!(name in this.events)) {
       throw new Error('No event declared using the name '+name);
    } else {
        this.events[name].forEach(function(handler) {
            handler.call(null,data);
        });
    }
}

var event =new EventDispatcher();

event.add('tick',function(data) {
    console.log("I have triggered by "+ data.name);
});

event.add('run',function(data) {
    console.log("I am running");
});

event.add('fly',function(data) {
    console.log("I am flying");
});


event.dispatch('tick', {name: 'rahul'});
event.dispatch('fly');
event.dispatch('run');