asp.net-mvc – Asp.Net MVC Ajax.BeginForm没有通过Ajax提交

<div id="contact-form" class="hidden" title="Online Request Form">
    @Using (Ajax.BeginForm("Contact","Main",Nothing,New AjaxOptions With {.UpdateTargetId = "status",.HttpMethod = "post"},New With {.id = "contactUs"}))
        @<div>
            @Html.LabelFor(Function(m) m.Name)<br />
            @Html.TextBoxFor(Function(m) m.Name)<br />
            @Html.LabelFor(Function(m) m.Phone)<br />
            @Html.TextBoxFor(Function(m) m.Phone)<br />
            @Html.LabelFor(Function(m) m.Email)<br />
            @Html.TextBoxFor(Function(m) m.Email)<br />
            @Html.LabelFor(Function(m) m.Question)<br />
            @Html.TextAreaFor(Function(m) m.Question)<br />
            @Html.LabelFor(function(m) m.Security)<br />
            @Html.TextBoxFor(Function(m) m.Security)<br />
            <noscript>
                <input type="submit" name="submit" value="Ok" />
            </noscript>
            @Html.ValidationSummary("Oops,please correct the errors.")<span id="status">@TempData("status")</span>
        </div>
    End Using
</div>

我在jQuery-UI模态窗口中打开它

<script>
    $(function () {

        // Open the modal dialog from the div.contact-us click event
        $('#contact-us').click(function () {
            $('#contact-form').dialog('open');
            return false;
        });

        // Manage the modal dialog behavior.
        $('#contact-form').dialog({
            modal: true,autoOpen: false,buttons: {
                Cancel: function () {
                    $(this).dialog('close');
                },Ok: function () {
                    $('form#contactUs').trigger('submit');
                }
            }
        });
    });

</script>

当我点击“确定”按钮,它发布到相应的控制器,但它不是通过AJAX发布

''# fix the StackOverflow code coloring issue.
    <HttpPost()>
    Function Contact(ByVal contactForm As Models.ContactForm) As ActionResult
        ViewData("Testimonials") = Helpers.GetTestimonials

        If ModelState.IsValid Then
            ''# Submit the email
            TempData("status") = "Thank you,we will be in touch"
        Else
            ''# Return False
            TempData("status") = "Oops,please correct the errors."
        End If


        If Request.IsAjaxRequest Then
            Return Content(TempData("status").ToString)
        Else
            Return View("Index")
        End If
    End Function

我究竟做错了什么？提交表单后,我的网址为http://example.com/Main/Contact,告诉我IsAjaxRequest = false

编辑

即使我不使用jquery-ui“ok”按钮,只需添加< input type =“submit”name =“submit”value =“Ok”/>以表格形式,没有Ajax的表单