mvc 怎样执行js 方法？？？

[cfsjjjj]

Index.cshtml 文件
@model WebApplication1.Models.shiti
@{
ViewBag.Title = "ceshi";
}
<script language="javascript" type="text/javascript">
function Success() {
alert("ok");
}
</script>

<h2>@ViewBag.Title。</h2>
@using (Ajax.BeginForm("Welcome", "HelloWorld", new AjaxOptions { HttpMethod = "POST",OnBegin= "Success",OnSuccess= "Success" }))
{
@Html.AntiForgeryToken()
<h4>cestj</h4>
.......省略
</div>
<div class="form-group">
<div class="col-md-offset-2 col-md-10">
<input type="submit" class="btn btn-default" value="提交" />
</div>
</div>
}



public class HelloWorldController : Controller
{
public ActionResult Index()
{
return View();
}
public ActionResult Welcome(Models.shiti st)
{
。。。。处理数据
return View(“Index”);
}
}
}


提交表单前表单后都没用执行Success方法,请问是怎么回事。写的位置不对吗？

[xiaojunjor]

<script src="~/Scripts/jquery.unobtrusive-ajax.min.js"></script>（没有的话Nuget里下载）