function get_extension($nom) {
    $nom = explode(".", $nom);
    $nb = count($nom);
    return strtolower($nom[$nb-1]);
}


$extensions_ok = array('jpg', 'jpeg');
$typeimages_ok = array(2);

$taille_ko = 1024;
$taille_max = $taille_ko*1024;
$dest_dossier = 'img/';