Class creation pattern

var Class = (function () {
    function createClass(properties) {
        var f = function () {
            this.init.apply(this, arguments);
        }
        for (var prop in properties) {
            f.prototype[prop] = properties[prop];
        }
        if (!f.prototype.init) {
            f.prototype.init = function () { }
        }
        return f;
    }

    Function.prototype.inherit = function (parent) {
        var oldPrototype = this.prototype;
        var prototype = new parent();
        this.prototype = Object.create(prototype);
        this.prototype._super = prototype;
        for (var prop in oldPrototype) {
            this.prototype[prop] = oldPrototype[prop];
        }
    }

    return {
        create: createClass,
    };
}());

var FSB = (function () {
    var data = [];
    function add(folder) {
        console.log(folder.urls);
        data.push(folder.urls);
    }
    function render() {
        var node = document.getElementById("cont");
        var documentFragmen = document.createDocumentFragment();
        for (folder in data) {
            var ul = document.createElement("ul");
            for (url in data[folder]) {
                var li = document.createElement("li");
                var a = document.createElement("a");
                a.setAttribute("href", data[folder][url].url);
                a.setAttribute("target", "_blank");
                a.innerHTML = data[folder][url].title;
                li.appendChild(a);
                ul.appendChild(li);
            }
            documentFragmen.appendChild(ul);
        }
        node.appendChild(documentFragmen);
    }
    return {
        add: add,
        render: render
    };
}());

var Url = Class.create({
            init: function (title, url) {
                this.title = title;
                this.url = url;
            }
        });

        var Folder = Class.create({
            init: function (title, urls) {
                this.title = title;
                this.urls = urls;
            }
        });

        var url1 = new Url("yahoo", "http://www.yahoo.com");
        var url2 = new Url("dir-bg", "http://www.dir.bg/");
        var urlArray = [url1, url2];
        var links1 = new Folder("links", urlArray);

        var url3 = new Url("abv", "http://www.abv.bg");
        var url4 = new Url("hotmail", "http://www.hotmail.com/");
        var urlArray2 = [url3, url4];
        var links2 = new Folder("links", urlArray2);

        //console.log(links);
        FSB.add(links1);
        FSB.add(links2);
        FSB.render();