如何获取自动完成中文本的id（值）

$(function () {
            $("input#txtactname").autocomplete({
                source: function (request, response) {
                    // define a function to call your Action (assuming UserController)
                    $.ajax({
                        url: '/Admin/GetActName?Acname=' + $("#txtactname").val(),
                        type: "POST",
                        dataType: "json",
                        // query will be the param used by your action method
                        data: { query: request.term },
                        success: function (data) {
                            response($.map(data, function (item) {
                                return { label: item, value: item };
                            }))
                        }
                    });
                },
                minLength: 3,
                select: function (event, ui) {
                    alert(this.value);
                    return false;
                }// require at least one character from the user
            }).result(function (event, item) {
                alert(item.value);
                $('#hdnactid').val(item.value);

            });



        });