function  showhidediv(divname) {
    var now;
    var d=document; // d ist alias für document
    // Abfrage für ns4
    if (d.layers) {
        now=d.layers[divname].visibility;
        d.layers[divname].visibility=(now=="show") ? "hide" : "show";
    // Abfrage für IE
    } else if (d.all) {
        now=d.all[divname].style.visibility;
        d.all[divname].style.visibility=(now=="visible") ? "hidden" : "visible";
    // Abfrage für NS7/mozilla
    } else if ((!d.all)&&(d.getElementById)) {
        now=d.getElementById(divname).style.visibility;
        d.getElementById(divname).style.visibility=(now=="visible") ? "hidden" : "visible";
    }
}