title: referencing an instantiated object in another class in objective C
body: <p>I am working in xcode on an ipod app in objective C, and I have a field (navigationController) in one of my classes (rootViewController).  How do I reference the instantiated rootViewController's navigationController from another class?  For example, how would I do this if I want to reference the navigationController from the FirstViewController.m class?  </p>
  
  <p>I seem to only be able to find references for this to reference the application delegate.  </p>
  
  <p>If I want to reference the application delegate with FirstViewController, I just say:</p>
  
  <pre><code>MyAppDelegate *delegate = [[UIApplication sharedApplication] delegate];
  
  [delegate.navigationController pushViewController:childController animated:YES];
  </code></pre>
  
  <p>how do I do this for the rootViewController class instead of MyAppDelegate?  </p>