CDNからのjquery読み込み失敗時のfallback処理

jquery

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js"></script>
<script>window.jQuery || document.write('<script src="jquery-1.7.1.min.js"><\/script>')</script>

jquery ui

<script src="https://ajax.googleapis.com/ajax/libs/jqueryui/1.8.16/jquery-ui.min.js"></script>
<script>window.jQuery.ui || document.write('<script src="jquery-ui-1.8.16.min.js"><\/script>')</script>