<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>
{/volist}
</select>
##<select name="tra_num">
<option value="" >全部</option>
(7 == 1 ?'selected':'')}>1</option>
<option value="2" { (7 == 2 ?'selected':'')lt;option value="2" { (7 == 2 ?'selected':'')lt;option>}>> ;/option>
<option value="4" { (7 == 4 ?'selected':'')}>4<mm " { ( 7 == 5 ?'selected':'')}>5</option>
<option value="6" { (7 == 6 ?'selected':''}> /option>
<option value="7" { (7 == 7 ?'selected':'')}>7<O;option> </ div>