function changePassword(email, newPassword, callback) {
  var mongo = require('mongojs@0.18.2');

  var db = mongo('mongodb://user:pass@mymongoserver.com/my-db');
  var users = db.collection('users');

  bcrypt.hash(newPassword, 10, function (err, hash) {
    if (err) {
      callback(err);
    } else {
      users.update({ email: email }, { $set: { password: hash } }, function (err, count) {
        if (err) return callback(err);
        callback(null, count > 0);
      });
    }
  });
}