แก้ตรงนี้ $sql= "select * from tb_class"; กับ $sql= "select * from tb_band where bn_mainb=1 ORDER BY 'bn_name' ASC "; หรือเปล่า
<script type=text/javascript>
var arrItems = new Array();
var arrItemsGrp = new Array();
var arrItemValue = new Array();
var arrItems2 = new Array();
var arrItemsGrp2 = new Array();
var arrItemsGrp3 = new Array();
var arrItemValue2 = new Array();