Hvad med dette stykke kode?

<select name="type" onchange="sh(this.value)" class="admin" size="1" id="admin_select">
        <option value="">text</option>
        <option value="radio">Radiobutton</option>
        <option value="primeremail">primerEmail</option>
        <option value="email">email</option>
        <option value="checkbox">checkbox</option>
        <option value="dropdown">dropdown</option>
        <option value="webadress">webadress</option>
        <option value="textarea">text area</option>
</select>
<script type="text/javascript">

actElm = false;
function sh(v) {
  if(actElm) {
    document.getElementById("drop_"+actElm).style.display="none";
    actElm = false;
  }
  if(document.getElementById("drop_"+v)) {
    document.getElementById("drop_"+v).style.display="block";
    actElm = v;
  }
}

</script>

<div id="drop_radio" style="display:none;">Radio checked</div>
<div id="drop_email" style="display:none;">Email checked</div>
<div id="drop_dropdown" style="display:none;">dropdown checked</div>

Genialt! Super mange tak.