function aff(id) { //menus déroulants
    if (document.getElementById(id).style.display == 'none') {
        document.getElementById(id).style.display = 'block';
    } else {
        document.getElementById(id).style.display = 'none';
    }
    return false;
}

function openLargeImage(representation, w, h, barre_de_titre) {
    var page = "/commun/image_ie.html?representation=" + representation + "&iw=" + w + "&ih=" + h;
    fenetre = window.open(page, 'images', 'location=no,toolbar=no,directories=no,menubar=no,resizable=no,left=' + ((screen.width - w) / 2) + ',top=' + ((screen.height - h) / 2) + ',scrollbars=0,status=no, width=' + w.toString() + ', height=' + h.toString());
    fenetre.focus();
    return false;
}