extends in javascript

function extend(subClass,superClass){
    var F = function(){};
    F.prototype = superClass.prototype;
    subClass.prototype = new F();
    subClass.prototype.constructor = subClass;
}


function Person(name){
    this.name = name;
}
Person.prototype.getName = function(){
    return this.name;
}

function Author(name,books){
    Person.call(this,name);
    this.books = books;
}
Author.prototype.getBooks = function(){
    return this.books;
}

extend(Author,Person);


var p = new Person("张三");
var a = new Author("刘畅");

console.log(p.getName());
console.log(a.getName());