Javascript class+call base class?
function BaseClass () {}

BaseClass.prototype.talk = function () {
    alert("I'm BaseClass");
}

function MyClass() {
    BaseClass.call(this);
}

MyClass.prototype = new BaseClass();
MyClass.base = BaseClass.prototype;

MyClass.prototype.talk = function () {
    alert("I'm MyClass");
    MyClass.base.talk.apply(this, arguments);
}

var a = new MyClass();
a.talk();


To make all this easier on yourself, don't re-invent the wheel. Look into John Resig's tiny inheritance library: Simple JavaScript Inheritance.