How to define an universal module?

module.js

(function(global) {
    
    function Person() {
        this.name = 'luozhihua';
        this.company = 'tbc.com';
    }

    Person.prototype = {
        say : function(words) {
            alert(words || "I can't say any more, you know that.");
        },

        set: function(key, value) {
            if (typeof key === 'string') {
                this[key] = value;
            }
        },

        get: function(key) {
            return this[key];
        }
    }

    // define as an amd module (require js)
    if (typeof global.define === 'module') {
        define([], function() {
            return Person;
        });

    // define as a cmd module (seajs or nodejs)
    } else if (module) {
        module.exports = Person;

    // define as a jquery plugins
    } else if (global.jQuery) {
        global.jQuery.fn.Person = Person;

    // define as a global variable
    } else {
        global.Person = Person;
    }

}(this));