$sql = "SELECT user_id,lastname,firstname,username FROM $tbl_user
$sql = "SELECT id,lastname,firstname,username FROM $tbl_user
WHERE active <> ".USER_SOFT_DELETED." AND ".$target_name." LIKE '".$first_letter_user_lower."%' OR ".$target_name." LIKE '".$first_letter_user_lower."%'
ORDER BY ".(count($users) > 0 ? '(user_id IN('.implode(',', $users).')) DESC,' : '').' '.$target_name;
ORDER BY ".(count($users) > 0 ? '(id IN('.implode(',', $users).')) DESC,' : '').' '.$target_name;