title: Add CATransition animation to UIViewControllers
body: <p>I want to add <code>CATransition</code> to <code>UIViewControllers</code> which i am displaying using <code>NSTimer</code></p>
  
  <pre><code>-(void)playAction:(id)sender
  {
  [audioPlayer play];
  [self performSelector:@selector(displayviewsAction:) withObject:nil afterDelay:11.0];
  }
  
  - (void)displayviewsAction:(id)sender
  {  
   First *firstController = [[First alloc] init];
   firstController.view.frame = CGRectMake(0, 0, 320, 480);
   [self.view addSubview:firstController.view];
   [self.view addSubview:toolbar];
   [firstController release];   
   self.timer = [NSTimer scheduledTimerWithTimeInterval:23 target:self selector:@selector(Second) userInfo:nil repeats:NO];     
   }
  
  -(void)Second 
  {
  Second *secondController = [[Second alloc] init];
  secondController.view.frame = CGRectMake(0, 0, 320, 480);
  [self.view addSubview:secondController.view]; 
  [self.view addSubview:toolbar];
  [secondController release];
  self.timer = [NSTimer scheduledTimerWithTimeInterval:27 target:self selector:@selector(Third) userInfo:nil repeats:NO];
  }
  </code></pre>
  
  <p>How i can add <code>CATransition</code> to these <code>UIViewControllers</code> when they change from first to second and so on.</p>
  
  <p>Thanks in advance for all ideas.</p>