Select triple a discesa anche con element non solo con form

<?php
//questa è una parte per indicare cosa intendo per form cioè $form
   $form['country'] = array(
      '#type' => 'select',
      '#ahah' => array(...........
      '#title' => t("Nazione"),............segue);
    $form['country_regions'] = array(
      '#type' => 'select',
      '#ahah' => array(...........
      '#title' => t("Regions country"),............segue);
    $form['country_cities'] = array(
      '#type' => 'select',
      '#title' => t("Country cities"),............segue);
    return $form;
 
?>

<?php
function cck_nations_related_select_process($element, $edit, &$form_state, $form) {
  $field_name = $element['#field_name'];
  $field = $form['#field_info'][$field_name];
  $field_key = $element['#columns'][0];
  if (is_array($element['#value']) && !array_key_exists($field_key, $element['#value'])) {
    $element['#value'] = optionwidgets_data2form($element, $element['#default_value'], $field);
  }
  $element[$field_key] = array(
    '#type' => 'select',
    '#title' => $element['#title'],
    '#description' => $element['#description'],
    '#required' => isset($element['#required']) ? $element['#required'] : $field['required'],
    '#multiple' => isset($element['#multiple']) ? $element['#multiple'] : $field['multiple'],
    '#options' => cck_nations_related_country_values(),
    '#default_value' => isset($element['#value'][$field_key]) ? $element['#value'][$field_key] : NULL,
  );
   $element['countryid'] = array(
    '#type' => 'select',
    '#title' => t("Country"),
    '#required' => TRUE,
    '#multiple' => FALSE,
    '#options' => cck_nations_related_country_values(),
    '#ahah' => array(
        'path' => 'cck_nations_related/resrenderelements-country',
        'wrapper' => 'ahah-wrapper-countryid',
        'effect' => 'fade',
        'event' => 'change',
        ),
  );
  //........altri elementi
  $form_state['#field_info']['cck_nations_related'] = $element;
  return $element;
}
//
function cck_nations_related_resrenderelements_country() {
  $form_state = array('submitted' => FALSE);
  $form_build_id = $_POST['form_build_id'];
  $form = form_get_cache($form_build_id, $form_state);
  if (!$form_build_id) {
    drupal_set_message(t('An unrecoverable form_build_id: %form_build_id', array('%form_build_id' => print_r($form_build_id))), 'error');
    print drupal_to_js(array('data' => theme('status_messages')));
    exit;
  }
  //questo post funziona
  $countryid = $_POST['countryid'];
  $result_regions = db_query("SELECT ........ WHERE $countryid")
  //questa select non funziona più e non so perchè
  $form['regionid'] = array(
          '#type' => 'select',
          '#title' => t("Regions"),
          '#required' => FALSE,
          '#options' => $opt_country_regions,
          '#prefix' => '<div id="ahah-wrapper-countryid">',
          '#suffix' => '</div>',
          '#ahah' => array(
             'path' => 'cck_nations_related/resrenderelements-regions',
             'wrapper' => 'ahah-wrapper-cityid',
             'event' => 'change',
             'effect' => 'fade',
             'method' => 'append',
           ),
      );
//............
  $output = drupal_render($form[regionid]);
  drupal_json(array('status' => TRUE, 'data' => $output));
  exit;
}
?>