What to attach event listener to in Drupal behavior I have a use case where I need to listen to the insertIntoActiveEditor event in the insertIntoActiveEditor event in the Insert module, but with this code:

(function ($) {

/**
 * Custom behavior to generate image style derivatives on S3 when an image is
 * inserted into the WYSWIYG editor.
 */
Drupal.behaviors.generateDerivative = {
  attach: function(context, settings) {
    $(document).on('insertIntoActiveEditor', function(event, data) {
      var test = 'a';

    })
  }
}
})(jQuery);


I'm getting an error that says 

Uncaught TypeError: $(...).on is not a function


on this line

$(document).on('insertIntoActiveEditor', function(event, data) {


I thought I had that syntax correct, but apparently I don't. Do I need to change my selector to be the Insert button (the same as is used in the module JS)? I"ve tried changing it to 

$('input[value="Insert"]').on('insertIntoActiveEditor', function(event, data) {


but I still get the same error.

Thanks.
The cause was pretty basic - this is in the admin theme, which in Drupal 7 is set to use jQuery 1.4.4, and .on() wasn't added until 1.7. I switched to using .bind(), and it works fine now.