I'm having trouble programming a simple sprite animation with four frames.

I've tried with a for-loop and with this ImageView.animationImages thing, I recently found on a youtube video. When I run each of those two programs it only shows the first frame.

I have followed a step-by-step instruction and found out that there is only one difference between the instruction-video and what I do:
the line:
@property (nonatomic, retain) IBOutlet UIImageView *imageView;
is different colored.

"UIImageView" is purple in the instructors source code while it's black in mine.
apparently my interface interprets the line different...

Schubidu, Lautsprech