Uncaught referenceerror is not defined

Question

Why and how does the written code give a result as an Uncaught ReferenceError: $ is not defined although it was working earlier?

$(document).ready(function() 
$('#tabs > ul').tabs({ fx: { opacity: 'toggle' } }); 
$('#featuredvid > ul').tabs(); });

The given results do not close now in the tabs despite having the jQuery being referenced in the header. What is the solution for this?
 

<script language="JavaScript" type="text/javascript" src="<?php echo get_option('siteurl') ?>/js/sprinkle.js"></script> <script language="JavaScript" type="text/javascript" src="<?php echo get_option('siteurl') ?>/js/jquery-1.2.6.min.js"></script> <script language="JavaScript" type="text/javascript" src="<?php echo get_option('si

Answer 1

The references must be aligned or put in an order in respect to the script of jquery right at the start. It has been explained below:-

<script language="JavaScript" type="text/javascript" src="/js/jquery-1.2.6.min.js"></script> 
<script language="JavaScript" type="text/javascript" src="/js/jquery-ui-personalized-1.5.2.packed.js"></script> 
<script language="JavaScript" type="text/javascript" src="/js/sprinkle.js"></script>

In other words, a user should put the script reference to jquery script at the start and then followed by the jquery-ui. To conclude, start with jquery-x.x.x.min.js followed by the jquery-ui-xxxxxx.js.