[jQuery] Clone dont work. Why?

[jQuery] Clone dont work. Why?


<div class="add-more">
     <label for="empresas_coligadas_ou_filiais" class="label-
ecf">Empresas Coligadas ou Filiais</label>
     <input name="empresas_coligadas_ou_filiais" type="text"
maxlength="255" />
    <span class="bt-more"></span>
<span class="bt-less"></span>
</div>
    $('span.bt-more').bind('click', function(){
     var e = $(this).parent()[0];
        e.parent().clone().after(e);
    });
Where is the error?
Thanks.
Antonio