example with "User script" not working!!!

[Lucian Bumb]

Hello, 

I just found this library and I testing the examples, and  this http://knockoutmvc.com/UserScript is not working, more exactly, the AddLetter not working. 

I get the error that the controller/action not found:

here is a picture: (somewhere :));

The controller name, the actions, the models are identical with the example, I even tried to add HttpPosts, and allowget, and still not working

[HttpPost]
     public ActionResult AddLetter(UserScriptModel model)
     {
         model.AddLetter();
         return Json(model,JsonRequestBehavior.AllowGet);
 
     }

Any idea why is not working?

Thank you,