AJAX enabled & disabled

@model string
           
@{
    ViewBag.Title = "GetPeople";
    AjaxOptions ajaxOpts = new AjaxOptions { UpdateTargetId = "tableBody", InsertionMode= InsertionMode.Replace,
                                             Url = Url.Action("GetPeopleData") //确保javascript enable和disable时能正常显示
    };
}
<h2>
    GetPeople</h2>
<table>
    <thead>
        <tr>
            <th>
                First
            </th>
            <th>
                Last
            </th>
            <th>
                Role
            </th>
        </tr>
    </thead>
    <tbody id = "tableBody">
       @Html.Action("GetPeopleData", new { selectedRole = Model })
    </tbody>
</table>

@using(Ajax.BeginForm(ajaxOpts))
{
    <div>
        @Html.DropDownList("selectedRole", new SelectList(
new[] { "All" }.Concat(Enum.GetNames(typeof(Role)))))
        <button type="submit">
            Submit</button>
    </div>
}

<div>
    @foreach (string role in Enum.GetNames(typeof(Role)))
    {
        <div class="ajaxLink">
            @Ajax.ActionLink(role, "GetPeople",
　　　　　　new { selectedRole = role },
　　　　　　new AjaxOptions
　　　　　　{
    　　　　　　UpdateTargetId = "tableBody",
    　　　　　　Url = Url.Action("GetPeopleData", new { selectedRole = role })
　　　　　　})
        </div>
    }
</div>