matcbox & user friendly links

[eluser]omerorhan[/eluser]
First of all i am sorry for my english.

i am trying to make my own cms system. i am using matchbox.

My links are like that:

www.mysite.com/contact_module/contact_us.

my directory structure is like:

aplication/modules/contact_module/controllers/start.php

i have defined a default controller for each modules. "start.php"

and in start.php i have a function like that

function index($link)
{
// here i do all the stuffs.
// and then view the result.
$this->load->view($this->config->item('template').'/index' ,$data);
}

Now, what i want to do is remove module_name from url. like www.mysite.com/contact_us.

I have to do something like, firstly check this $link belongs to which module from the database. Then make a call to the the related module's default controller. But how?

I hope i could explain my problem.

Thank you.

Orhan.