<form id="form_limit">
    <div class="row">
        <div class="dataTables_length" id="basicTable_promotion"></div>
    </div>
    <input type="hidden" id="promotionId" value="[[promotionId]]">

    <div class="panel-footer">
        <button class="btn btn-primary" id="save_multi">保存</button>
    </div>
</form>