Javascript Static Singleton

Singleton pattern for Javascript

HTML

<textarea id="test" rows="5"></textarea>

CSS

textarea {
    resize: none;
}

JavaScript

// Based on http://jsfiddle.net/timsommer/thxn4/ by Tim Sommer
var Singleton = (function () {
    // singleton class definition
    var _class = function Singleton() {
        this.name = "Singleton";
        this.pointX = 16;
    }
    // instance holder
    var instance;
    // emulation of static variables and methods
    return {
        name: 'Singleton',
        // get a singleton instance of class _singleton
        getInstance: function () {
            if (instance === undefined) instance = new _class();
            return instance;
        }
    };
})();

function log(message) {
	var output = document.getElementById("test");
	var lines = output.value.split("\n");
	lines.push(message);
	output.value = lines.join("\n");
}

var test = Singleton.getInstance();
log(test.pointX); // outputs 16
test.pointX = 15;
log(test.pointX); // outputs 15