title: Using ParseFacebookUtils to login android app with facebook
body: <p>I am working on an application that uses Parse and I want to login using Facebook.</p>
  
  <p>This is my code:</p>
  
  <pre><code>        Button facebook = (Button)findViewById(R.id.facebook);
      facebook.setOnClickListener(new View.OnClickListener() {
          public void onClick(View arg0) {
              ParseFacebookUtils.logIn(signUpStep2.this, new LogInCallback() {
                    public void done(ParseUser user, ParseException err){
                        if (user == null) {Log.d("My app", "NULL");}
   }                    else if (user.isNew()){Log.d("My app", "New User");}
                        else{Log.d("My app", "User");}
  </code></pre>
  
  <p>However, I am always getting a Null user, and a Null ParseException err.</p>
  
  <p>What is my error?</p>