MVC :: 3 - Ajax.actionlink Does Not Work

i have an application mvc3, created a link with ajax but confirm property does not works.

index.cshtml is
@{
View.Title = "Home Page";
}
@section Header{
<script src="../../Scripts/MicrosoftAjax.debug.js" type="text/javascript"></script>
<script src="../../Scripts/MicrosoftMvcAjax.debug.js" type="text/javascript"></script>
}
<h2>@View.Message</h2>
@Ajax.ActionLink(
"Delete Product",
"Delete",
new { id = 1 },
new AjaxOptions { HttpMethod = "DELETE", Confirm = "Are you sure?" }
)

and home controller delete action

public ActionResult Delete(int id)
{
return View();
}

but directly does delete page. how can i confirm box show?