I'm certainly not an expert on jCarousel, but I'm not seeing where you actually include it?
I see something that looks like a plugin for it:
<script src="jcarousel.data-attributes.js"></script>
But I would expect to see the actual jCarousel script before that:
<script type="text/javascript" src="jquery.jcarousel.js"></script>
UPDATE:
What I mean, is that your full list of scripts needed in order to make this work are:
<script type="text/javascript" src="jquery.js"></script>
<script type="text/javascript" src="jquery.jcarousel.js"></script>
<script type="text/javascript" src="jcarousel.data-attributes.js"></script>
You need to have jQuery included, which you already do. You also need to have jCarousel included, which you currently do not. You just need to include that before the data-attributes plugin to make everything work.