jquery select change下拉框选项变化判断选中值

<th class="formTitle">
    是否转出：
</th>
<td class="formValue" colspan="3">
    <select id="IsTurnOut" class="txtselect required" datacol="yes" err="是否转出" checkexpession="NotNull">
        <option value=""></option>
        <option value="是">是</option>
        <option value="否">否</option>
    </select>
</td>

$("#IsTurnOut").change(function () {
            var ss = $(this).children('option:selected').val();
            if (ss == "是") {

            } else if (ss == "否") {

            }
        });