How to use base_url() in js file

[eluser]keld[/eluser]
Hi, I'm trying to use base_url() into a javascript file that I've renamed .js.php because I'm making an ajax request like this:

Code:

...
var qt=$(this).find('select[name=fieldname]').val();
$.post(<?php echo base_url(); ?>.'/admin/dashboard/getStuff', {var: qt, ajax:'1'},...
...

How do I make the base_url accessible from here? I can add this at the top of my myscript.js.php file

Code:

$this->load->helper('url');

The problem is that my js folder is outside the application folder.

Thanks a lot!