$ not defined in JavaScript

Question

Firebug is reporting that

$ is not defined [Break On This Error] $(function(){

I have a simple index.php page that does a php include to include the contents I

Answer 1

Add this before your script tag. It uses google's CDN.

<script type="text/javascript" src="//ajax.googleapis.com/ajax/libs/jquery/1.5.1/jquery.min.js"></script>

Answer 2

Are you including jQuery at the top of your script?

Answer 3

Did you include the jQuery library?