Adding a new parameter values list and use it

CREATE TABLE IF NOT EXISTS `country` (
  `id` int(12) unsigned NOT NULL AUTO_INCREMENT,
  `code` varchar(4) DEFAULT NULL,
  `lang` varchar(2) DEFAULT NULL,
  `name` varchar(100) DEFAULT NULL,
  `idle` int(1) unsigned DEFAULT '0',
  PRIMARY KEY (`id`),
  UNIQUE KEY `countryCodeLang` (`code`,`lang`),
  KEY `countryCode` (`code`),
  KEY `countryLang` (`lang`)
) ENGINE=InnoDB  DEFAULT CHARSET=utf8 AUTO_INCREMENT=1 ;

INSERT INTO `country` VALUES(1, 'af', 'en', 'Afghanistan', 0);
INSERT INTO `country` VALUES(2, 'af', 'fr', 'Afghanistan', 0);
INSERT INTO `country` VALUES(3, 'al', 'en', 'Albania', 0);
INSERT INTO `country` VALUES(4, 'al', 'fr', 'Albanie', 0);
INSERT INTO `country` VALUES(5, 'dz', 'en', 'Algeria', 0);
INSERT INTO `country` VALUES(6, 'dz', 'fr', 'Algérie', 0);
INSERT INTO `country` VALUES(7, 'ad', 'en', 'Andorra', 0);
INSERT INTO `country` VALUES(8, 'ad', 'fr', 'Andorre', 0);
(…)

INSERT INTO `menu` VALUES(135, 'menuCountry', 36, 'object', 710, NULL, 0);

<?php 
/* ============================================================================
 * Country defines list of countries.
 */ 
require_once('_securityCheck.php');
class Country extends SqlElement {

  // extends SqlElement, so has $id
  public $_col_1_2_Description;
  public $id;    // redefine $id to specify its visible place
  public $code;
  public $lang;
  public $name;
  
  // Define the layout that will be used for lists
  private static $_layout='
    <th field="id" formatter="numericFormatter" width="10%"># ${id}</th>
    <th field="code" width="10%">${code}</th>    
    <th field="lang" width="10%">${lang}</th>
    <th field="name" width="70%">${name}</th>
    ';

  private static $_fieldsAttributes=array("code"=>"required", 
                                          "lang"=>"required",
                                          "name"=>"required" 
  );    
  
   /** ==========================================================================
   * Constructor
   * @param $id the id of the object in the database (null if not stored yet)
   * @return void
   */ 
  function __construct($id = NULL) {
    parent::__construct($id);
  }

  
   /** ==========================================================================
   * Destructor
   * @return void
   */ 
  function __destruct() {
    parent::__destruct();
  }

// ============================================================================**********
// GET STATIC DATA FUNCTIONS
// ============================================================================**********
  
  /** ==========================================================================
   * Return the specific layout
   * @return the layout
   */
  protected function getStaticLayout() {
    return self::$_layout;
  }
     /** ==========================================================================
   * Return the specific fieldsAttributes
   * @return the fieldsAttributes
   */
  protected function getStaticFieldsAttributes() {
    return self::$_fieldsAttributes;
  }
  
}
?>

public $idCountry;