title: Won't return to my app after logging into FB app
body: <p>I apologize if this is stupid question but I just started trying to incorporate the FB SDK into my app today.</p>
  
  <p>I followed the instructions online and got to the point where they suggested testing the app. The FB app opened as expected and asked permission as expected. However when I accepted the FB app stayed open instead of going back to my app. </p>
  
  <p>I think it may have to do with the access token keys. I found online how to get this key, but should I enter it in the code shown below? What about the expiration date key? Or are these generated dynamically? </p>
  
  <pre><code>facebook = [[Facebook alloc] initWithAppId:@"##########" 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"];
  }
  </code></pre>
  
  <p>Thanks!</p>
  
  <pre><code>if (![facebook isSessionValid]) {
      [facebook authorize:nil];
  }
  </code></pre>