public function setup(&$element, $value, $group = null)
 {
     parent::setup($element, $value, $group);
     $this->joomla_field = new RokCommon_Form_JoomlaFieldWrapper($element, $group, $value, $this->name, $this->id);
     if ($this->joomla_field === false) {
         return false;
     }
     $this->joomla_field->setRokCommonForm($this->form);
     return true;
 }