function _image_100p($reg) {
    $img = $reg[1];
    $img = vider_attribut($img, "width");
    $img = vider_attribut($img, "height");
    $img = vider_attribut($img, "style");

    $img = inserer_attribut($img, "style", "max-width: 100%; height: auto;");
    return $img;

}

function image_100p($texte) {
    return preg_replace_callback(",(<img\ [^>]*>),", _image_100p, $texte);
}