title: MVC 4 (razor) - Controller is returning a partialview but entire page is being updated
body: <p>I'm new to MVC 4 and the Razor engine - so this might be a dumb question.</p>
  
  <p>What I'm trying to achieve is I have a page with a drop down list and a button.  Clicking the button calls the controller passing the value selected.  The controller should return a partial view and only the bottom part of the page should be updated.</p>
  
  <p>However I'm finding that the entire page gets replaced with just the partial view html.  Ie. I get my list of results displaying but I lose my dropdownlist of projects and submit button.  I tried including a reference to jquery and unobtrusive scripts (which I don't think I need to in MVC 4) but that doesn't change the page at all (ie. the dropdownlist and button stay there and no results are displayed).</p>
  
  <p>Part of my View:</p>
  
  <pre><code>@using (Ajax.BeginForm("GetProjectStories", "MyController", new AjaxOptions{ UpdateTargetId = "projectUserStories"}))
  {
  
      &lt;fieldset&gt;
          &lt;legend&gt;Select Project&lt;/legend&gt;
          &lt;div&gt;
              @Html.DropDownList("ProjectReference", (IEnumerable&lt;SelectListItem&gt;)Model.ProjectList)
          &lt;/div&gt;
          &lt;p&gt;
          &lt;input name="GetStoriesButton" type="submit" value="Get Stories" /&gt;
          &lt;/p&gt;
      &lt;/fieldset&gt;
  }
  
  @if (Model != null &amp;&amp; Model.UserStories != null)
  {
      &lt;div id="projectUserStories"&gt;
          @{Html.RenderPartial("_UserStoryList", Model);}
      &lt;/div&gt;
  
  }
  </code></pre>
  
  <p>My controller:</p>
  
  <pre><code>public ActionResult GetProjectStories(ProjectViewModel model)
          {
  
             var stories =  MyService.GetProjectUserStories(model.ProjectReference).Results;   
             model.UserStories = stories;
              return PartialView("_UserStoryList", model);
          }
  </code></pre>
  
  <p>My partial view content just contains an html table and reference to the model.</p>