User Authentification

Hi =)

I'm getting started with yii, and have read Larry's tutorial. I know my question must be silly, but I'm a bit confused. I've found this tutorial fur user creation http://www.yiiframework.com/doc/guide/1.1/en/topics.auth and I'm surprised how easy it seams to be to create a user auth system. But I don't know where to create this code...

Before I've read this tutorial, I had created a "user" table with login, password , name etc field, and wanted to bind them with the login feature automatically inserted in yii, but it didn't seam to be the right approach...

Can anyone guide me a little bit through this problem?

Thanks a lot!