$() Is Not A Function

The good old problem - I am loading the .js file by default with

<script src="<?php echo Yii::app()->request->baseUrl; ?>/js/selectBoxIt.js"></script>

And im still getting the an error like:

TypeError: $(...).selectBoxIt is not a function

I guess I should registerScript or something like that, but I still dont know how.

I think you can not include jquery so please include a lastest jquery on default view