Asp.net MVC Loading Parent View from the actionlink of PartialView using Ajax not working

I have a situation where I need to call ParentView from its partial view. Like I have list of ToDos in Partial view where Ajax actionlink is used to edit the data in parent by passing its id. The same is working without using Ajax as it is manipulating url by putting querystring. But we would like to have internal call with Ajax which is not firing.

The code we are using is like that:

<li>@Ajax.ActionLink(@item.ToDoTitle, "Index", new { tdid = @item.ToDoId }, new AjaxOptions { UpdateTargetId = "saved", InsertionMode = InsertionMode.Replace, HttpMethod="POST" })</li>

and controller is like that:

public ActionResult Index(int tdid =0)
    {
        if (tdid !=0)
        {
            ToDo t = new ToDo();
            t.ToDoTitle = "Ramlal";
            t.ToDoDesc = "Shyamlal";
            t.ToDoId = tdid;
            return Json(t);
        }
        else
        {
            return View();
        }
    }