Classes (EcmaScript 5)

classes-es5.js

function Person(name) {
   this.name = name;
}

Person.prototype.saysHello = function () {
   return "Hello, my name is " + this.name;
};

function Employee(name, title) {
   Person.call(this, name);
   this.title = title;
}

Employee.prototype = new Person();
Employee.prototype.constructor = Employee;

Employee.prototype.describe = function () {
   var parent = Person.prototype.saysHello.bind(this);
   return parent() + " (" + this.title + ")";
};