why webgrid always pass default

问题:

i make editable webgrid, when i pass value for webgrid, i allways give default value for checkbox. when value in database is "TRUE", after edited checkbox to false, value will pass "TRUE" seams like value in database. can some one help me

this my view

<div>
    @{
        var grid = new WebGrid(Model.DataDiriList, rowsPerPage: 15, canPage: true, canSort: true, ajaxUpdateContainerId: "gridContent");
        @grid.GetHtml(
                           tableStyle: "row",
                  alternatingRowStyle: "alt",
                  columns: grid.Columns(
                  grid.Column("ID", format: @<text>  <span  class="display-mode">@item.ID </span> <label id="UserID" class="edit-mode">@item.ID</label> </text>, style: "col1Width" ),
                  grid.Column("Nama", "Nama", format: @<text>  <span  class="display-mode"> <label id="lblNama"  >@item.Nama</label> </span> <input type="text" id="Nama" value="@item.Nama" class="edit-mode" /></text>, style: "col2Width"),
                  grid.Column("Umur", "Umur", format: @<text>  <span  class="display-mode"> <label id="lblUmur"  >@item.Umur</label> </span> <input type="text" id="Umur" value="@item.Umur" class="edit-mode" /></text>, style: "col2Width"),
                  grid.Column(header: "Active", format:@<text> <span  class="display-mode"> @Html.Raw("<input type=\"checkbox\" " + ((item.Active == true) ? "checked='cheked'" : "") + "disabled = 'disabled'/>") </span> <input id="chkActive" type="checkbox" @(item.Active ? " checked=checked" : null) name="CloseSelling" value="@item.Active" class="edit-mode" /></text>, style: "col2Width"),
                  grid.Column("Action", format: @<text>
                                <button class="edit-user display-mode" >Edit</button>
                                <button class="save-user edit-mode"  >Save</button>
                                <button class="cancel-user edit-mode" >Cancel</button>
                            </text>,  style: "col3Width" , canSort: false)
                 ));
    }
</div>

@section scripts
    {
    <script type="text/javascript">

        $(document).ready(function () {
            $('.edit-mode').hide();
            $('.edit-user, .cancel-user').on('click', function () {
                var tr = $(this).parents('tr:first');
                tr.find('.edit-mode, .display-mode').toggle();
            });



            $(".save-user").on("click", function () {
                var tr = $(this).parent().parent();
                var t = tr.find("#Nama").val();
                var Umur = tr.find('#Umur').val();
                var ID = tr.find('#UserID').html();
                var chkActive = tr.find('#chkActive').val();

                $.ajax({
                    url: '@Url.Action("UpdateUser", "Home")',
                type: "Post",
                data: { CustomerNameId: t, UserID: ID, Umur: Umur,Active: chkActive},
                dataType: 'json',
                success: function (result) {
                    $("#mygrid").html('');
                    $("#mygrid").html(result);
                }
                });

                tr.find("#lblNama").text(t);
                tr.find("#lblUmur").text(Umur);
                tr.find('.edit-mode, .display-mode').toggle();
        });

    });
</script>
    }

MY Controller

public JsonResult UpdateUser(string CustomerNameId, string UserID, string Umur, bool Active)
        {
            var ID = Convert.ToInt32(UserID);
            var IntUmur = Convert.ToInt32(Umur);
            var dd = db.DataDiris.AsQueryable().Where(r => r.ID == ID).Single();
            dd.ID = ID;
            dd.Nama = CustomerNameId;
            dd.Umur = IntUmur;

            db.Entry(dd).State = EntityState.Modified;
            db.SaveChanges();
            string message = "Success";
            return Json(message, JsonRequestBehavior.AllowGet);
        }