JSON -- populate two textboxes after user SELECTION ?

Currently everything gets saved into
@Html.TextBox("productDescription")
which I do NOT want.

How can I change below code so step #4 populates
@Html.TextBox("productName") with selected c.PartNumber
and @Html.TextBox("productDescription") with its
associated c.PartDescription ?

Steps
 1. user enters data into @Html.TextBox("productName")
 2. search automatically populates @Html.TextBox("productName")
    with possible c.PartNumber --->  c.PartDescription) results
 3. user selects a results
 4. @Html.TextBox("productName") gets updated with
    selected c.PartNumber --->  c.PartDescription)
----------------------------------------------------
AutoCompleteController.cs

        public JsonResult getData(string term)
        {

            var mySearchResults = db.Lookup_PartNumbers
                                    .Where(c => c.PartNumber.Contains(term) || c.PartDescription.Contains(term))
                                    .Select(c => c.PartNumber + "  --->  " + c.PartDescription)
                                    .Take(10);

            return Json(mySearchResults, JsonRequestBehavior.AllowGet);
        }

--------------------------------------------------------------------------------------------------------
Index.cshtm

l
    <script type="text/javascript">
        $(function () {
            $('#productName').autocomplete({
                source: function (request, response) {
                    $.getJSON("/AutoComplete/getData?term=" + request.term, function (data) {
                        response(data);
                    });
                },
                minLength: 2,
                delay: 100
            });
        });
    </script>

               Product: @Html.TextBox("productName")
                Description: @Html.TextBox("productDescription")