I'm using passport for user authentication and it is working fine, but i wan't to change the message 'Unauthorized' when the user login or password is wrong.

Here is the code for the user authentication:

app.get('/login', function(req, res){
  res.render('login');
})

app.post('/login', function(req, res){
  const user = new User({
    username: req.body.username,
    password: req.body.password
  });

  req.login(user, function(err){
    if(err){
      res.send('Erro')
    } else{
      passport.authenticate('local')(req, res, function(){
        if(user){
          res.send('Positive')
        } else{
          res.send('Negative')
        }
      })
    }
  })

});

It returns 'positive' if the user type the correct login and password, but if the login and password is wrong, it returns 'Unauthorized' instead of 'negative'