title: UINavigationController error crashing my app
body: <p>I am trying my first UINavigationController app and it is now crashing.  If I comment out the line that starts with navController, I don't crash, but if course the app doesn't work either. </p>
  
  <p>(Note: My environment is IOS 4.2 and Xcode 3.2)</p>
  
  <pre><code>(BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {    
  
      WpglViewController *firstViewController = [[WpglViewController alloc] init];    
  
      navController = [[UINavigationController alloc] initWithRootViewController:firstViewController];
  
      [firstViewController release];
  
      [window addSubview:navController.view];
  
      [self.window makeKeyAndVisible];
  
      return YES;
  }
  </code></pre>
  
  <p>Here is the crash information.  Can someone point me in the right direction?  Thanks for the help.
  <br></p>
  
  <pre><code>2011-09-04 07:59:49.309 wpgl[7302:207] -[WpglViewController title]: unrecognized selector sent to instance 0x4b134c0
  2011-09-04 07:59:49.313 wpgl[7302:207] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[WpglViewController title]: unrecognized selector sent to instance 0x4b134c0'
  *** Call stack at first throw:
  
  (
      0   CoreFoundation                      0x00ecdbe9 __exceptionPreprocess + 185
      1   libobjc.A.dylib                     0x00cc25c2 objc_exception_throw + 47
      2   CoreFoundation                      0x00ecf6fb -[NSObject(NSObject) doesNotRecognizeSelector:] + 187
      3   CoreFoundation                      0x00e3f366 ___forwarding___ + 966
      4   CoreFoundation                      0x00e3ef22 _CF_forwarding_prep_0 + 50
      5   UIKit                               0x00375781 -[UINavigationController pushViewController:transition:forceImmediate:] + 743
      6   UIKit                               0x0036e4a0 -[UINavigationController pushViewController:animated:] + 62
      7   UIKit                               0x00370d98 -[UINavigationController initWithRootViewController:] + 78
      8   wpgl                                0x00001df9 -[wpglAppDelegate application:didFinishLaunchingWithOptions:] + 146
      9   UIKit                               0x002b81fa -[UIApplication _callInitializationDelegatesForURL:payload:suspended:] + 1163
      10  UIKit                               0x002ba55e -[UIApplication _runWithURL:payload:launchOrientation:statusBarStyle:statusBarHidden:] + 439
      11  UIKit                               0x002c4db2 -[UIApplication handleEvent:withNewEvent:] + 1533
      12  UIKit                               0x002bd202 -[UIApplication sendEvent:] + 71
      13  UIKit                               0x002c2732 _UIApplicationHandleEvent + 7576
      14  GraphicsServices                    0x016e4a36 PurpleEventCallback + 1550
      15  CoreFoundation                      0x00eaf064 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__ + 52
      16  CoreFoundation                      0x00e0f6f7 __CFRunLoopDoSource1 + 215
      17  CoreFoundation                      0x00e0c983 __CFRunLoopRun + 979
      18  CoreFoundation                      0x00e0c240 CFRunLoopRunSpecific + 208
      19  CoreFoundation                      0x00e0c161 CFRunLoopRunInMode + 97
      20  UIKit                               0x002b9fa8 -[UIApplication _run] + 636
      21  UIKit                               0x002c642e UIApplicationMain + 1160
      22  wpgl                                0x00001d44 main + 102
      23  wpgl                                0x00001cd5 start + 53
  )
  terminate called after throwing an instance of 'NSException'
  </code></pre>
  
  <p>In my WpglViewController.h file I have the following declared:</p>
  
  <pre><code>@interface WpglViewController : NSObject &lt;UIApplicationDelegate&gt;
  
  {
      UILabel *servingsLabel;
      UILabel *quantityLabel;
      UINavigationController *navigationController;
  }
  
  @property (nonatomic, retain) IBOutlet UILabel *servingsLabel;
  @property (nonatomic, retain) IBOutlet UILabel *quantityLabel;
  @property (nonatomic, retain) IBOutlet UIWindow *window;
  @property (nonatomic, retain) UINavigationController *navigationController;
  
  @end
  </code></pre>
  
  <p>and in my WpglViewController I have the following declared:</p>
  
  <pre><code>#import "WpglViewController.h"
  
  @implementation WpglViewController
  
  @synthesize servingsLabel;
  @synthesize quantityLabel;
  @synthesize navigationController;
  </code></pre>