Why can't I push a new view controller onto the current view?

Question

I am using the following code and getting the following errors:

Answer 1

I'm going to say that you've not imported ChangePasscode.h in your current file.

Update: In response to comment thread below, you'll need to actually create a nav structure if you want to push view controllers. The preferred way in iOS 5 is as follows:

// AppDelegate.h
// …Other existing code
@property (nonatomic, retain) UINavigationController *navController;
@end

// AppDelegate.m
@synthesize navController;
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
  navController = [[UINavigationController alloc] initWithRootViewController:viewController];
  self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
  self.window.rootViewController = navController;
  self.window.backgroundColor = [UIColor whiteColor];
  [self.window makeKeyAndVisible];
  return YES;
}