Extending the controller class

[eluser]richzilla[/eluser]
Hi All,

When extending the controller class, does it have to contain the name of the class that it is extending?

for example MY_Controller contains the name of the controller class that it is extending. The reason i ask is that i am attempting to extend the controller class twice, once for the admin part of my site and once for the normal 'site'. Ive named the new classes MY_Site and MY_Admin and placed them both in the libraries folder, however this does not seem to work, as nothing is generated when i request pages that implement these classes? any help would be appreciated.