title: Adding left button to UINavigationBar (iPhone)
body: <p>I've created a new navigation based iPhone app.  I added this to the RootViewController.</p>
  
  <pre><code>- (void)viewDidLoad {
      [super viewDidLoad];
      UIBarButtonItem *addButton = [[UIBarButtonItem alloc] init];
  self.navigationItem.leftBarButtonItem = addButton;
  self.navigationItem.leftBarButtonItem.enabled = YES;
  }
  </code></pre>
  
  <p>No left button displays however.  Is there something I need to do?</p>