load jQuery from external source if not loaded

Question

load jQuery from source

What I like to do is to drop my local jquery.js and have it hosted somewhere else. But what if Google is down? So let's code a fallback that uses another source if jQuery is "still" not loaded...

I made this test case but it does not seem to work, maybe someone can help me out:

http://jsfiddle.net/RBz4n

Answer 1

This works fairly well (from HTML5 Boilerplate):

<!-- Grab Google CDN's jQuery. fall back to local if necessary -->
<script src="//ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.js"></script>
<script>!window.jQuery && document.write(unescape('%3Cscript src="js/libs/jquery-1.4.2.js"%3E%3C/script%3E'))</script>