title: Sending custom error message from Express JS over to Backbone
body: <p>In express js, I have the following code which sends a response over to Backbone:</p>
  
  <pre><code>if (!user) {
      req.session.messages = [info.message];
      return res.send(400, howCanIsendTheErrorMessageAlso);
  }
  </code></pre>
  
  <p>How can I send the error message also, together with the error code?</p>
  
  <p><strong>How can Backbone receive it?</strong></p>
  
  <p>Any ideas?</p>
  
  <p>In backbone, I have the following code:</p>
  
  <pre><code>loginModel.save({
      username : obj.elEmail.val(),
      password : obj.elPassword.val(),
      admin : false
  }, {
      success: function (e) {
          console.log('success');
      }, 
      error: function (e) {
          console.log(e);
      }   
  });
  </code></pre>
  
  <p>Any ideas?</p>