Faire apparaitre un formulaire de selection

<select id="MyId1" name="MyName1">
   <option value="" selected="selected">Fabricant...</option>
   <option value="1">1</option>
   <option value="2">2</option>
...
</select>
<select id="MyId2" name="MyName2" style="display: hidden;">
   <option value="1" selected="selected">1</option>
   <option value="2">2</option>
...
</select> 

<script type="text/javascript">
$('#MyId1').change(function () {
   if( this.value == '' ) {
       $('#MyId2').hide();
   } else {
       $('#MyId2').show();
   }
}).change();
</script>

<form id="form_recherche" onsubmit="document.location='http://www.jeuxvideo.fr/recherche/redirect.php?textrecherche='+escape(qf.recherche.value)+'&cat='; return false;" action="#" method="post" name="qf">
     <fieldset>
         <legend class="nodisplay">Rechercher sur Jeuxvideo.fr</legend>
         <input id="rech_text" type="text" name="recherche" value="Un jeu, une vidéo, une démo, ..."/>
         <input id="rech_submit" type="submit" title="Recherche" value=""/>
     </fieldset>
</form>

#searchwith .mots_cle {ccm.css?...807221035 (ligne 1875)
   background:transparent url(/img/sprite_ccm.png) repeat scroll -609px -123px;
   border:medium none;
   color:#2E333C;
   float:left;
   font-size:12px;
   height:17px;
   margin:2px 0 0;
   padding:4px 0 0 90px;
   width:119px;
}

<select id="MyId1" name="MyName1">
   <option value="1" selected="selected">1</option>
   <option value="2">2</option>
...
</select>
<select id="MyId2" name="MyName2" style="display: hidden;">
   <option value="1" selected="selected">1</option>
   <option value="2">2</option>
...
</select>