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

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

function User(name, password) {
	this.name = name;
	this.password = password;
}

User.prototype = new Person();

User.prototype.getPassword = function(){
	return this.password;
};

var user = new User('KEN', 'backdrop');

console.log(user.getName(), user.getPassword());