Can't load external javascript code

Hello,
I'm trying to load an external javascript code inside a view from my project, but the browser can't find.

The javascript is found on: localhost/diceroller/assets/js/script.js
My index.php is found on: localhost/diceroller

The load external javascript code is in my view:

Code:

<script src='<?php echo base_url("assets/js/script.js"); ?>' type='text/javascript' ></script>

On Firefox, when I press F12 I found on console that say the following:

Code:

Falha no carregamento do <script> com a fonte “http://localhost:8080/diceroller/assets/js/script.js”
(Failed to load <script> with source "http://localhost:8080/diceroller/assets/js/script.js")

As you can see, the script.js is on localhost/diceroller/assets/js/ but the browser can't find on that folder.