Prototype pattern in JavaScript

person.js

var Person = function(name, age){
  this.setName(name);
  this.setAge(age);
};

Person.prototype = {
  getName : function(){
    return this._name;
  },
  setName : function(name){
    this._name = name;
  },
  setAge : function(age){
    this._age = age;
  },
  getAge: function(){
    return this._age;
  },
  introduction: function(){
    return "Hello World, I am " + this.getName();
  }
}

///////////////

var p = new Person("Narendra", 32);
p.introduction();