public function add_field_data($field)
 {
     if ($field->type == 'role') {
         $field->display = 'selectbox';
         $field->values = isset($_REQUEST[$field->code]) ? (array) $_REQUEST[$field->code] : array();
         $field->options = bd_pseudo_role_field_get_available_roles();
     }
     return $field;
 }
 /**
  * Get member types as associative array
  * 
  * @staticvar array $roles array( 'role'=> Label'
  * @return array
  */
 private static function get_roles()
 {
     static $roles = null;
     if (isset($roles)) {
         return $roles;
     }
     $roles = bd_pseudo_role_field_get_available_roles();
     return $roles;
 }