title: UILabel becomes null after facebook login (UILabel dosen't update)
body: <p>I am working on adding facebook SSO and the SDK to my project. All of my main facebook code is in my <code>AppDelegate.m</code> and <code>AppDelegate.h</code>.
  In my view controller <code>[[[UIApplication sharedApplication] delegate] performSelector:@selector(callLogin)];</code> is called when I press a button.
  The callLogin method in my <code>AppDelegate.m</code> looks like this:</p>
  
  <pre><code>- (void)callLogin{
  
  facebook = [[Facebook alloc] initWithAppId:@"XXXXX" andDelegate:self];
  
  NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
  if ([defaults objectForKey:@"FBAccessTokenKey"] 
      &amp;&amp; [defaults objectForKey:@"FBExpirationDateKey"]) {
      facebook.accessToken = [defaults objectForKey:@"FBAccessTokenKey"];
      facebook.expirationDate = [defaults objectForKey:@"FBExpirationDateKey"];
  }
  
  if (![facebook isSessionValid]) {
      [facebook authorize:nil];
      }
  }
  </code></pre>
  
  <p>Then in my <code>- (void)fbDidLogin</code> method I call the method <code>setInfo</code> which is located in my viewcontroller.</p>
  
  <pre><code>//this method is located in AppDelegate.m
  - (void)fbDidLogin {
  NSLog(@"FACEBOOK DID LOGIN");
  ViewController * vc = [[ViewController alloc]init];
  [vc setInfo]; 
  }
  </code></pre>
  
  <p>Finally, here is my <code>-(void)setInfo</code> code which is located in <code>ViewController.m</code></p>
  
  <pre><code>-(void)setInfo{
  infoL.text = [NSString stringWithFormat: @"Connected to Facebook!"];
  NSLog(@"%@",infoL);
  //NSLog returns null
  } 
  </code></pre>
  
  <p>From setInfo I am unable to change the label and NSLog returns that <code>infoL</code> is null. I can update the label through methods like ViewDidLoad, but not setInfo.
  What am I doing wrong and how can I fix this?</p>