ASP.NET MVC 4 AJAX提交表单不工作

在我看来,我有：

@{
        ViewBag.Title = "Users > Edit";
        var options = new AjaxOptions()
                          {
                              Url = Url.Action("Edit","User"),LoadingElementId = "saving",LoadingElementDuration = 2000,Confirm = "Are you sure you want to save this User?"
                          };  
    }

    <div id="saving" style="display:none; color:Red; font-weight: bold"> 
         <p>Saving...</p> 
    </div> 

    @using (Ajax.BeginForm(options)) 
    {
        @Html.ValidationSummary(true)
        <fieldset>
            .... FIELDS ...
            <p>
                <input type="submit" value="Save" />
            </p>
        </fieldset>
    }

当点击提交按钮时,正在执行完整的回发.我的动作方法如下所示：

[HttpPost]
public ActionResult Edit(User user)
{
    if (ModelState.IsValid)
    {
        _repository.Save(user);
        TempData["message"] = String.Format("{0} has been saved.",user.Username);
    }

    return View(user);
 }

有没有我失踪的东西？ MVC 4目前的版本有几个问题吗？

在我的Web.Config我确实有ClientValidationEnabled和UnobtrusiveJavaScriptEnabled设置为true.

我也在我的_Layout.cshtml中指定了这些：

<script src="@Url.Content("~/Scripts/jquery.validate.min.js")" type="text/javascript"></script>
    <script src="@Url.Content("~/Scripts/jquery.validate.unobtrusive.min.js")" type="text/javascript"></script>