title: how to do a continuous recycling UIView animation
body: <p>The following code move the the imageview from right to left once, but I want to do continously.  move right to to left then move back to left offscreen and repeat right to left again.</p>
  
  <pre><code>imageview=[[UIImageView alloc] initWithFrame:CGRectMake(320, 200, 2635, 200)];
  
  image=[UIImage imageWithContentsOfFile:[[NSBundle mainBundle] pathForResource:@"animal" ofType:@"png"]]; 
                 [imageview setImage:image];
  
  [self.view addSubview:imageview];
  
  [UIView beginAnimations:@"MoveAndStrech" context:nil];
  [UIView setAnimationDuration:40];     //30
  [UIView setAnimationBeginsFromCurrentState:YES];
  CGPoint p, b, a, c, d,e;
  p.x = 0;
  p.y = 200;
  
  imageview.center=p;
  
  [UIView commitAnimations];  
  </code></pre>