for($i=0;$i<count($_POST['no_bill']);$i++){
$_no_bill=$_POST['no_bill'][$i];
$_detail=$_POST['detail'][$i];
$_amount=$_POST['amount'][$i];
           if($_POST['no_bill'][$i]!=""||$_POST['detail'][$i]!=""||$_POST['amount'][$i]!="")
     {
        $sql3="insert into  tb_receipt_voucher_detail(ref_id,no_bill,detail,amount) values('$id','$_no_bill','$_detail','$_amount')";
        echo $sql3."</br>";
  $result3=mysql_db_query($dbname,$sql3);
     }

}

ขอบคุณครับ