title: Remove class not working with MooTools
body: <p>I'm using the following piece of code in my webpage to change the class of select elements depending on the choice of a radio button. </p>
  
  <p>The part where I add the class works fine but the other (where I remove them) doesn't work. I get no error in the Error console and when I changed my code to have the part that removes the class put another class to the select elements it worked fine.</p>
  
  <pre><code>&lt;script type="text/javascript"&gt;
    window.addEvent('domready', function(){
     $('votconj').addEvent('click', function() {
       // This works fine
       $('first_name_conjoint').addClass("validate['required','nodigit']");
       $('last_name_conjoint').addClass("validate['required','nodigit']");
       $('jj_conjoint').addClass("validate['required']");
       $('mm_conjoint').addClass("validate['required']");
       $('aaaa_conjoint').addClass("validate['required']");
       $('conjoint_regime').addClass("validate['required']");
       new FormCheck('formulaire');
     });
  
     $('votconj_no').addEvent('click', function() {
       // This doesn't work !
       $('first_name_conjoint').removeClass("validate['required','nodigit']");
       $('last_name_conjoint').removeClass("validate['required','nodigit']");
       $('jj_conjoint').removeClass("validate['required']");
       $('mm_conjoint').removeClass("validate['required']");
       $('aaaa_conjoint').removeClass("validate['required']");
       $('conjoint_regime').removeClass("validate['required']");
       new FormCheck('formulaire');
     });
  
  
     new FormCheck('formulaire');
  });
  &lt;/script&gt;
  
  
  // The radio button
  &lt;label&gt;Conjoint :&lt;/label&gt;
      &lt;input type="radio" name="votconj" id="votconj" value="oui"&gt;oui
      &lt;input type="radio" name="votconj" id="votconj_no" value="non" checked="checked"&gt;non
  </code></pre>