function QueryOneValue($sql,$etiquette,$value)
{
  $stmt = $bd->prepare($sql);
  $stmt->bindValue($etiquette, $value);
  if ($stmt->execute()===false) {
    throw new Exception('Erreur execution '.$sql);
  }
}

$info_pays_resid = QueryOneValue("select pays from avs_pays WHERE id_pays=:id_pays",":id_pays",$pays_resid);