ASP.NET MVC - using the same form to both create and edit

<%@ Page Language="C#" Inherits="System.Web.Mvc.ViewPage<NerdDinner.Models.Dinner>" MasterPageFile="~/Views/Shared/Site.Master"  %>
<asp:Content ID="Title" ContentPlaceHolderID="TitleContent" runat="server">
    Host a Nerd Dinner
</asp:Content>
<asp:Content ID="Create" ContentPlaceHolderID="MainContent" runat="server">
    <h2>Host a Dinner</h2>
    <% Html.RenderPartial("DinnerForm"); %>
</asp:Content>

<%@ Page Language="C#" Inherits="System.Web.Mvc.ViewPage<NerdDinner.Models.Dinner>"
    MasterPageFile="~/Views/Shared/Site.Master" %>
<asp:Content ID="Title" ContentPlaceHolderID="TitleContent" runat="server">
    Edit: <%:Model.Title %>
</asp:Content>
<asp:Content ID="Edit" ContentPlaceHolderID="MainContent" runat="server">
    <h2>Edit Dinner</h2>
    <% Html.RenderPartial("DinnerForm"); %>
</asp:Content>

<%@ Language="C#" Inherits="System.Web.Mvc.ViewUserControl<NerdDinner.Models.Dinner>" %>
<script src="/Scripts/MicrosoftAjax.js" type="text/javascript"></script>
<script src="/Scripts/MicrosoftMvcAjax.js" type="text/javascript"></script>
<script src="/Scripts/MicrosoftMvcValidation.js" type="text/javascript"></script>
<% Html.EnableClientValidation(); %>
<%: Html.ValidationSummary("Please correct the errors and try again.") %>
   <% using (Html.BeginForm())
      { %>
   <fieldset>
       <div id="dinnerDiv">
           <%:Html.EditorForModel() %>
           <p>
               <input type="submit" value="Save" />
           </p>
       </div>
       <div id="mapDiv">
           <%: Html.EditorFor(m => m.Location) %>
       </div>
   </fieldset>
   <% } %>