Thank you shokinro for your quick reply! I tried to change the Country.php and put it in override foulder.
As my version is 1.6.1.4, actually the code was not same. It was like below.
if ($list_states) {
$result = Db::getInstance(_PS_USE_SQL_SLAVE_)->ExecuteS('SELECT * FROM `'._DB_PREFIX_.'state` ORDER BY `name` ASC');
foreach ($result as $row) {
if (isset($countries[$row['id_country']]) && $row['active'] == 1) { /* Does not keep the state if its country has been disabled and not selected */
$countries[$row['id_country']]['states'][] = $row;
}
}
}
return $countries;
I changed the part of"name" to "iso_code".
It works now perfectly! Thank you sooooooo much!!