[Help]How to work with controllers in separate folders

[eluser]Nonox[/eluser]
I have a doubt about how to work with controllers in separate folders, part of the site is into a folder called "site/", and all this is what the users surf (the main site), the folder "admin/" have the controllers about the administration.

Well... all refer about "admin/" is OK, I navigate in this way http://localhost/admin/login .

But I dont want to navigate the main site in this way:
http://localhost/site/catalog/product/1
I want this way:
http://localhost/catalog/product/1

I followed this recomendation http://ellislab.com/codeigniter/user-gui...subfolders

I hope you can help me to solve this.
Thanks
N

My structure of folder is this:

Code:

htdocs/
    system/
        application/
            config/
            controllers/
                admin/
                site/
            errors/
            helpers/
            hooks/
            languages/
            libraries/
            models/
                admin/
                site/
            views/
                admin/
                site/