jQuery Preloader - What am I doing wrong?

I'm attempting to add a jQuery preloader to my website by injecting the following into the header of my gallery home page - via Gallery Settings > Advanced > Page Header Code Injection.

It doesn't work though. I'm really new to this so does anyone have any idea what I am doing wrong?

<script src="http://princessandrea.com/jquery.queryloader2.js" type="text/javascript"></script>
<script type="text/javascript">
$(document).ready(function () {
    $("body").queryLoader2();
});
</script>

I have the JavaScript file uploaded at another host at the above domain because I don't even see how to upload files here on Squarespace. Thanks to anyone who can help!