How pass all item selected in of multi sellct drop downlist of MVC in java script

@Html.DropDownListFor(model => model.SelectedUnitOfCompanyFID, ViewBag.unit as List<SelectListItem>, new { @class = "example-multiple-selected", id = "unit-multisel", multiple = "multiple" })

<pre>   <script type="text/javascript">


        $(document).ready(function () {

            $("#unit-multisel").change(function () {




            
                var SelectedVal = $('#unit-multisel').val();

                var jsonval = JSON.stringify(SelectedVal);
             


                $("#rdbgroup-multisel").html('');
              
                if (SelectedVal != '') {

                    $.get('/Account/getgrouplist/',

                        {


                            "orgFId": jsonval
                        }).success(function (data) {


                            $.each(data, function (index, item) {
                                $("#rdbgroup-multisel").append($("<option></option>").attr("value", item.uf)
                                    .text(item.description));



                            });


                            $('select#rdbgroup-multisel').multiselect('rebuild');


                        });
                }
            });
        })

    </script>