extend_javascript

function extend(Child, Parent) {

var F = function () {};
F.prototype = Parent.prototype;
Child.prototype = new F();
Child.prototype.constructor = Child;
Child.uber = Parent.prototype;

}
// Using this function (or your own custom version of it) helps you keep your code clean with regard to the repetitive inheritance-related tasks. This way you can inherit by simply using:
// Copy
extend(TwoDShape, Shape);

function extend(child,parent){
var F = function();
 F.prototype = parent.prototype;
 child.prototype = new F()
 child.prototype.constructor = child;
}