dynamic pages (from db) problem

[eluser]gn90at[/eluser]
Hi together

first of all: my english is bad. i am from austria...i hope u can read it.

i am working with CodeIgniter since 2 weeks. i made a few small projects and now i want to create my own cms for one site (admin_panel).

in the admin panel i can create a new site (eg "About") and i save the site with some content in a DB. (id, name, content).

in the frontend, i got my own Sites Controller and a Site_model.

Frontend:
its like a newssystem (like in the tutorial of the CodeIgniter Userguide) but just for sites. The problem is the URL. when i got a Controller "Sites" it will produces URLs like this:

http://www.mysite.com/sites/about

But i want URLs like this:
http://www.mysite.com/about

i also got other Controllers with a fix URL (each of them got a own Controller):

http://www.mysite.com/contact
http://www.mysite.com/gallery
http://www.mysite.com/news
...

i think i need a function who checks if the controller exist and when not check if the site is in DB... something like that?

i know the _remap() function of CodeIgniter. But it only takes the second segment of the URL. But i want a URL as i described above.

is there any way to make a dynamic controller with such URLs?

Hope u can help me.

And again: sry for my english

Best regards GN