title: Can't call success function
body: <p>I'm developing a Backbone Node.js with Express.js app. I'm trying to trigger a function after receiving a response from my server like the code bellow:</p>
  
  <p><strong>mainView.js</strong></p>
  
  <pre><code>...
  
  user: null,
  
  initialize: function () {
       _.bindAll(this, 'registerSuccess', 'loginSuccess');
       this.user = new userModel();
  }
  
  registerSuccess: function () {
       this.user.auth({
            success: this.loginSuccess
       });
  });
  
  loginSuccess: function () {
      console.log('loginSuccess');
  }
  </code></pre>
  
  <p><strong>userModel.js</strong></p>
  
  <pre><code>  ...  
  
  , auth: function (options) {
       $.ajax({
            url: 'users/auth'
          , type: 'post'
       }, options);
  })
  </code></pre>
  
  <p><strong>app.js</strong></p>
  
  <pre><code>var api = require('./routes/apiController');
  
  app.post('/users/auth', api.userAuth);
  </code></pre>
  
  <p><strong>apiController.js</strong></p>
  
  <pre><code>exports.userAuth = function (req, res) {
  
      return res.send( { 
         status: 200
      });
  
  }
  </code></pre>
  
  <p><strong>I´m getting the response:</strong></p>
  
  <p><img src="https://i.stack.imgur.com/Xuap8.png" alt="enter image description here"></p>
  
  <p>But it doesn't print the <code>console.log('loginSuccess')</code> sentence from this function.</p>