function Person(name, age, job){

            this.name = name;

            this.age = age;

            this.job = job;

            this.friends = ["Shelby", "Court"];

        }

        Person.prototype = {

            constructor: Person,

            sayName : function () {

                alert(this.name);

            }

        };

        var person1 = new Person("Nicholas", 29, "Software Engineer");

        var person2 = new Person("Greg", 27, "Doctor");

        person1.friends.push("Van");

        alert(person1.friends);    //"Shelby,Court,Van"

        alert(person2.friends);    //"Shelby,Court"

        alert(person1.friends === person2.friends);  //false

        alert(person1.sayName === person2.sayName);  //true