Currently I have one page to my umbraco site with one Document type called 'HomePage'

I have added a custom controller which returns my home page veiw, that works fine.
 
From that same view I am trying to post the data from a form, I have created an action in the same controller to to handle the post called 'Contact'

I have given it the attibuite [HttpPost] but when I submit the form I am not able to hit that controller I just get 'Page not Found', this is my code:

    public class HomePageController : RenderMvcController
     {
       public override ActionResult Index(RenderModel model)
       {  
           return View("HomePage");
        }  

        [HttpPost]
        public ActionResult Contact(FormCollection c)
{
//I WANT TO PROCESS MY FORM DATA HERE
        }

<form id="contact-form" action="HomePage/Contact" method="post">

<input id="name" class="rounded" name="contact[name]" type="text" />

<input id="email" class="rounded" name="contact[email]" type="text" />

<input id="submit-mail" class="submit-btn rounded" type="submit" value="SEND MESSAGE" />

</form>

I found this post: http://www.systenics.com/blog/creating-an-ajax-enabled-contact-form-in-umbraco-6-with-aspnet-mvc-4-and-twitter-bootstrap/?tag=Umbraco+6

Which talks about haddling a form post, but it involes making a new document type to represent the form, and it gos on... but what I want to know is......... Is it really necessary to do this? Surely there must be a simple way just to post the back to the controller that renders it..?

Any ideas?