title: Express.js response is not defined error
body: <p>I'm trying to implement a simple login, but there's a small issue.
  <code>bcrypt</code> returns a <code>response</code>, so when I try to <code>res.send("stuff")</code>, it returns an error since it thinks that I'm trying to access a property of the res object rather than express.js's response feature. (correct me if I'm wrong).</p>
  
  <blockquote>
    <p>ReferenceError: response is not defined at authController.js:79:21</p>
  </blockquote>
  
  <pre><code>exports.loginModalPost = function (req, res) {
      // post
      var email = req.body.email;
      var password = req.body.password;
  
      // email &amp; password validation.
      user.where('email', email).fetch().then(function (data) {
          if (data) {
              data = data.toJSON();
              bcrypt.compare(password, data.password_hash, function (err, res) {
                  if(res === true) {
                      res.send("login is valid");
                  } else {
                      // return err, but don't say that password is wrong to the end user.
                      res.send("password is wrong");
                  }
              });
          } else {
              // email is wrong, no need to check password.
              // return err, but don't say that email is wrong.
              res.send("email is wrong");
          }
      });
  };
  </code></pre>