title: Casting sender parameter
body: <p>I have a method that accepts a sender and is called with a UIbutton. How do I get that object to casted into a UIImageView? Basically how do I re-use the code for the button.</p>
  
  <pre><code>- (IBAction)startClick:(id)sender { 
      button.animationImages = [NSArray arrayWithObjects:
                                         [UIImage imageNamed:@"Pic_1.png"],
                                         [UIImage imageNamed:@"Pic_2.png"],
                                         [UIImage imageNamed:@"Pic_3.png"],
                                         nil];
      [button setAnimationRepeatCount:1];
      button.animationDuration = 1;
      [button startAnimating];
  }
  </code></pre>