MVC2 Application's Submit Button Returns URL With An Appended "Form"?

OK, I'm sorry if the tile of the question was unclear, and if you understand what I mean, please don't hesitate to help me think of a better one.

Anyway, I have a <input type="submit"> element for my form, and I want it to return the same URL as the URL of the page the element is on.

Currently, if I click the button, it takes me from /Calculate/Quadratic to /Calculate/QuadraticForm

In my controller for this view, I have the following code:

[AcceptVerbs(HttpVerbs.Get)]
public ViewResult Quadratic()
{
ViewData["Root1"] = "";
ViewData["Root2"] = "";
return View();
}
[AcceptVerbs(HttpVerbs.Post)]
public ViewResult Quadratic(QuadCalc boss)
{
ViewData["Root1"] = x1;
ViewData["Root2"] = x2;
return View();
}

And here is the markup and code for my Quadratic view page, which includes the form which includes the submit button I've been referring to:

<asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="server">
<h2>Quadratic</h2>
<% using(Html.BeginForm("QuadraticForm", "Calculate")) %>
<% { %>
<div>
a: <%= Html.TextBox("quadraticAValue") %>
<br />
b: <%= Html.TextBox("quadraticBValue") %>
<br />
c: <%= Html.TextBox("quadraticCValue") %>
<br />
<input type="submit" id="quadraticSubmitButton" value="Calculate!" />
<br />
<p><%= ViewData["Root1"] %></p>
<p><%= ViewData["Root2"] %></p>
</div>
<% } %>
</asp:Content>

Therefore, all I really want is to have the submit button return the same page, but the HTTP post will aid the application in passing new ViewData. Unless I'm interpreting this all wrong.