<select name="tra_num">
??????? <option value="" {$num_tra=="%"?'selected':''}>全部</option>
??????? {volist name="list_tra" id="arr_tra" empty="沒有文章"}
??????? <option value="{$arr_tra.id}" { {$num_tra} == {$arr_tra.id} ?'selected':''}>{$arr_tra.id}</option>
???