A custom Events utility that works in IE9 and everywhere else

Custom_Events_Everywhere.js

var trigger = function trigger(eventName, elem, data) {
    var evt;
    data = data || undefined;
    try {
        evt = new CustomEvent(eventName, {detail: data});
    } catch (e) {
        evt = document.createEvent('CustomEvent');
        evt.initCustomEvent(eventName, true, true, data);
    }
    elem.dispatchEvent(evt);
};