if (document.images) {            // Active Images

            startseiteon = new Image();
            startseiteon.src = "/_img/startseite_1.gif";
            aktuellon = new Image();
            aktuellon.src = "/_img/aktuell_1.gif";
            praxisspektrumon = new Image();
            praxisspektrumon.src = "/_img/praxisspektrum_1.gif";
            opspektrumon = new Image();
            opspektrumon.src = "/_img/opspektrum_1.gif";
            unserteamon = new Image();
            unserteamon.src = "/_img/unserteam_1.gif";
            kooperationspartneron = new Image();
            kooperationspartneron.src = "/_img/kooperationspartner_1.gif";
            kontakton = new Image();
            kontakton.src = "/_img/kontakt_1.gif";
            impressumon = new Image();
            impressumon.src = "/_img/impressum_1.gif";

            startseiteoff = new Image();
            startseiteoff.src = "/_img/startseite_0.gif";
            aktuelloff = new Image();
            aktuelloff.src = "/_img/aktuell_0.gif";
            praxisspektrumoff = new Image();
            praxisspektrumoff.src = "/_img/praxisspektrum_0.gif";
            opspektrumoff = new Image();
            opspektrumoff.src = "/_img/opspektrum_0.gif";
            unserteamoff = new Image();
            unserteamoff.src = "/_img/unserteam_0.gif";
            kooperationspartneroff = new Image();
            kooperationspartneroff.src = "/_img/kooperationspartner_0.gif";
            kontaktoff = new Image();
            kontaktoff.src = "/_img/kontakt_0.gif";
            impressumoff = new Image();
            impressumoff.src = "/_img/impressum_0.gif";

        }

// Function to 'activate' images.
function imgOn(imgName) {
        if (document.images) {
            document[imgName].src = eval(imgName + "on.src");
        }
}

// Function to 'deactivate' images.
function imgOff(imgName) {
        if (document.images) {
            document[imgName].src = eval(imgName + "off.src");
        }
}