Backend setup

[eluser]Ajaxian64[/eluser]
Hi all,
(I use CI 2.0)

I try to set up a backend with the objective to well separated code between front-end and back-end

Then I set up a new directory siteadmin in controllers directory
I also set up in routes.php

Code:

$route['site-admin'] = 'siteadmin/login';

Nevertheless when I have this url => http://mySite/siteadmin then It would seem that I can't reach login controller in my siteadmin directory.
I have a 404 http error sayingthat /mySite/siteadmin can't be found on this server

Does someone know something about this ?

Thanks