// precarica le immagini

if (document.images)
    {
    img1on = new Image(161, 39);
    img1on.src = "./img/date_on.jpg";
    img2on = new Image(195, 49);
    img2on.src = "./img/danza_on.jpg";
    img3on = new Image(296, 53);
    img3on.src = "./img/teatro_on.jpg";
    img4on = new Image(281, 41);
    img4on.src = "./img/coll_on.jpg";
    img5on = new Image(190, 45);
    img5on.src = "./img/chi_on.jpg";


    img1off = new Image(161, 39);
    img1off.src = "./img/date_off.jpg";
    img2off = new Image(195, 49);
    img2off.src = "./img/date_on.jpg";
    img3off = new Image(296, 53);
    img3off.src = "./img/teatro_off.jpg";
    img4off = new Image(281, 41);
    img4off.src = "./img/coll_off.jpg";
    img5off = new Image(190, 45);
    img5off.src = "./img/chi_off.jpg";

    }