function Employee(name, title) {
  Person.call(this, name); // super(name)
  this.title = title;
}
Employee.prototype = Object.create(Person.prototype);
Employee.prototype.constructor = Employee;
Employee.prototype.describe = function() {
  return Person.prototype.describe.call(this) // super.describe()
         + ' (' +  this.title + ')';
};

Employee.prototype.constructor = Employee;