(function () {
  //////////////////////////////
  // Add event (cross browser)
  // From http://stackoverflow.com/a/10150042
  //////////////////////////////
  function addEvent(elem, event, fn) {
    if (elem.addEventListener) {
      elem.addEventListener(event, fn, false);
    } else {
      elem.attachEvent('on' + event, function() {
        // set the this pointer same as addEventListener when fn is called
        return(fn.call(elem, window.event));
      });
    }
  }
  
  // Example usage
  addEvent(window, 'load', function () {
    var $ = window.jQuery;
    // Do something

  });
  
  addEvent(document, 'DOMContentLoaded', function () {
    var $ = window.jQuery;
    // Do something
  
  });
})();