is require_once required in CI?

[eluser]mason22[/eluser]
[quote author="Ben Edmunds" date="1261198138"]No they do. Check your default extension in config.php. And make sure you put MY_Controller in the libraries folder.[/quote]

"no they do" as in there is an easier way? I assumed there was a way for CI to automatically load it by looking at the prefix. My prefix is set to MY_ but it still comes up with errors.

this is the error that I get....

Fatal error: Class 'MY_Common' not found in /opt/lampp/htdocs/test/system/application/controllers/contact.php on line 3