Interface Builder - Event on UIButton?

Alright... my first post here and I am pretty stuck

I create a simple UI using IB..

I have a tabbar .. which loads its view from an external xib file. in this external xib file i have the file's owner as a custom UIViewController class.. and inside I dragged a UIView .. now so far everything works fine.. when i run it in simulator i can see the view loaded and everything

Now i wanted to add a UIButton to the UIView and handle the "event" on the UIButton in the UIViewController class..

any idea how an i do it?

when I create an IBOutlet UIButton* button; in my UIViewController class it crashes on me.. how can i do this then?

any tips?

thanks