You're using jQuery 1.6.4 in the page which doesn't support the on()
method. This was only introduced in version 1.7 http://api.jquery.com/on/
Edit
As well as the lines you have included there are two scripts loading older versions. These are the referencing lines. They must be getting pulled in from your wordpress template.
<script type='text/javascript' src='http://b.pusku.com/wp-includes/js/jquery/jquery.js?ver=1.7.2'></script>
<script type='text/javascript' src='http://b.pusku.com/wp-content/themes/wpbootstrap/bootstrap/js/jquery.js?ver=3.4.2'></script>