class less Event Emitter in 20 lines

eventEmitter.js

function eventEmitter() {
        var events = {};
        return {
            bind: function bind(name, cb) {
                events[name] = events[name] || [];
                events[name].push(cb);
            },
            unBind: function unBind(name, cb) {
                if (!events[name]) return;
                events[name].splice(events[name].indexOf(cb), 1);
            },
            trigger: function trigger(name) {
                if (!events[name]) return;
                var args = arguments;
                events[name].forEach(function (cb) {
                    cb.apply(null, Array.prototype.slice.call(args, 1));
                });
            }
        }
    };