A way to have classes in Javascript

class.js

// Orginial version from John Resig (http://ejohn.org/blog/simple-javascript-inheritance/)

(function(){
    var initializing = false, fnTest = /xyz/.test(function(){xyz;}) ? /\b\__super\b/ : /.*/;

    this.Class = function(){};

    this.Class.create = function(prop) {
        var super = this.prototype, name, prototype;

        initializing = true;
        prototype = new this();
        initializing = false;

        for (name in prop) {
            prototype[name] = typeof prop[name] == "function" &&
                typeof super[name] == "function" && fnTest.test(prop[name]) ?
                (function(name, fn){
                    return function() {
                        var tmp, ret;
                        
                        try {
                            tmp = this.__super;
                            this.__super = super[name];
                            ret = fn.apply(this, arguments);
                        } finally {
                            this.__super = tmp;
                        }

                        return ret;
                    };
                })(name, prop[name]) :
                prop[name];
        }
        
        function Class() {
            if (!initializing && this.__init)
                this.__init.apply(this, arguments);
        }
        
        Class.prototype = prototype;
        Class.prototype.constructor = Class;
        Class.extend = arguments.callee;

        return Class;
    };
})();