title: viewcontroller not found in appdelegate.m file
body: <p>I am following the ios tutorial to incorporate Facebook into my app. Everything went fine until I got to the part about adding a logout button. I keep getting an error stating property "ViewController" not found on object of type. What am I doing wrong? Here is the code from my appdelegate.m file. </p>
  
  <pre><code>-(BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {    
  
      // Add the requests dialog button
      UIButton *requestDialogButton = [UIButton buttonWithType:UIButtonTypeRoundedRect];
      requestDialogButton.frame = CGRectMake(40, 150, 200, 40);
      [requestDialogButton setTitle:@"Send Request" forState:UIControlStateNormal];
      [requestDialogButton addTarget:self 
                              action:@selector(requestDialogButtonClicked)
                    forControlEvents:UIControlEventTouchUpInside];
      [self.viewController.view addSubview:requestDialogButton];
      // ...
  }
  </code></pre>