title: Check if Stackmob has created a new Facebook user
body: <p>I am using Facebook as one option to create a user account for my iOS app. </p>
  
  <p>I am using createUserIfNeeded to create a new user account with stackmob. But how do I check if an account was already created previously and this is not a new account? (i.e stack mob is just logging in an existing user) </p>
  
  <p>I need this information as if a new user was just created, I want to create a new user profile. Otherwise the user will obviously already have a profile and I won't want to create another for the same user.</p>
  
  <pre><code>[self.client loginWithFacebookToken:FBSession.activeSession.accessTokenData.accessToken createUserIfNeeded:YES usernameForCreate:user.username onSuccess:^(NSDictionary *result)
  {
          NSLog(@"Logged in with StackMob");
  
          } onFailure:^(NSError *error) {
  
          NSLog(@"Error: %@", error);
      }];
  </code></pre>
  
  <p>}</p>