MVC :: ActionResult Not Called From Input?

to make sure, that my problem is not made by myself i create a new mvc solution and added following code into Views/Home/Index.aspx:

[Code]....

The corresponding HomeController was added by following Code:

[AcceptVerbs(HttpVerbs.Post)]
public ActionResult SendMail(string username, string email, string subject, string message)
{
ViewData["Message"] = "Mail was sended....";
return View();
}

The ActionResult was not called - what do i have to do else? What do i forget?

I made a look to the Orange-Template where i found to do it in that way and in that Template it works.