因为jQuery UI需要jQuery库.

请参见错误日志$ is undefined，因为它们不是像funcName()那样的函数，而是jQuery函数$.funcName()和其他必需的jQuery函数.

See in error log, $ is undefined, because they are not functions like funcName() but jQuery functions $.funcName() with other jQuery functions required.

<script src="http://code.jquery.com/ui/1.10.3/jquery-ui.js"></script>

现在加载jQuery.但是错误仍然来自UI.

Now load jQuery. But error is still from UI.

<script src="http://code.jquery.com/jquery-2.0.3.js"></script>