Uncaught ReferenceError: a is not defined at HTMLDocument.<anonymous> code example
Example 1: reference error $ is not defined jquery
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
Example 2: register:48 Uncaught ReferenceError: $ is not defined
<script src="//ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>