Avoiding Fallback Loading Script From CDN

You can use jQuery scripts hosted on CDN in your Web application by adding the following script element to a page: 

    <script src="http://ajax.aspnetcdn.com/ajax/jquery/jquery-1.9.0.js"></script>                        

To allow your page to fallback to loading jQuery from a local path on your own website if the CDN happens to be unavailable, add the following element immediately after the element referencing the CDN:

    <script>
        // Fallback to loading jQuery from a local path if the CDN is unavailable
        (window.jQuery || document.write('<script src="/scripts/jquery-1.9.0.min.js"><\/script>'));
    </script>