jQuery构造求解,该怎么解决

jQuery构造求解
话说jQuery的代码我没看太懂，请各位高人指点一下，下面代码是我依葫芦画瓢瞎写的，似乎能做到fm1和fm2的区别对待。但是还是不理解为什么我把this.settings移动到跟version平级的位置，就不行，那个this难道不是fn吗？请详解，困惑！

JScript code

(function (window) {    var floatMenu = function (settings) {        return new floatMenu.fn.init(settings);    };    floatMenu.fn = floatMenu.prototype = {        version: "1.0",        init: function (settings) {            this.settings = {};            util.extends(this.settings, settings);        },        load: function () {            return this.settings.hello;        }    }    floatMenu.fn.init.prototype = floatMenu.fn;    var util = {        extends: function (collection, collectionOverride) {            if (collectionOverride && collection) {                for (var key in collectionOverride) {                    collection[key] = collectionOverride[key];                }            }        }    };    if (window) {        window.$fm = window.floatMenu = floatMenu;    }})(window);var fm1 = $fm({ "hello": "world2" });var fm2 = $fm({ "hello": "world3" });alert(fm1.load());alert(fm2.load());alert(fm1.load());alert(fm2.load());

JScript code

function (settings) {            this.settings = {};            util.extends(this.settings, settings);}