Hide/Show DIV's on multiple select values

<select id="term" name="form_select">
    <option value="0">Choose term</option>
    <option value="1">Month</option>
    <option value="2">Week</option>
    <option value="3">Day</option>
</select>
<select id="season" name="form_select">
    <option value="0">Choose season</option>
    <option value="1">Low</option>
    <option value="2">Hight</option>
    <option value="3">Peak</option>
</select>

tr_ad_lowmonth
tr_ad_lowweek
tr_ad_lowday
tr_ad_hightmonth
tr_ad_hightweek
tr_ad_hightday
tr_ad_peakmonth
tr_ad_peakweek
tr_ad_peakday

$('#term, #season').on('change', function() {
 $('div[id^="ad_"]:gt(3)').css("display","none");

      var term   = $.trim( $('#term :selected').text().toLowerCase() ),
      season = $.trim( $('#season :selected').text().toLowerCase() );
 if($('#term :selected').val() > 0 && $('#season :selected').val() > 0)   {
          var $sel = '#ad_' + season + term;
          $($sel).css("display","block");

   }

});

#ad_lowmonth,
#ad_lowweek,
#ad_lowday,
#ad_hightmonth,
#ad_hightweek,
#ad_hightday,
#ad_peakmonth,
#ad_peakweek,
#ad_peakday {
display:none;
}