browserName = navigator.appName;
browserVer = parseInt(navigator.appVersion);
if (browserName == "Netscape" && browserVer <= 4) version = "2";
else if (browserName == "Microsoft Internet Explorer" && browserVer <= "3") version = "2";
else version = "1";

if (document.images && version=="1") {
sitemapakt = new Image();
sitemapakt.src = "/grafiken/top-sitemap-over.gif";
sucheakt = new Image();
sucheakt.src = "/grafiken/top-suche-over.gif";
kontaktakt = new Image();
kontaktakt.src = "/grafiken/top-kontakt-over.gif";

sitemap = new Image();
sitemap.src = "/grafiken/top-sitemap.gif";
suche = new Image();
suche.src = "/grafiken/top-suche.gif";
kontakt = new Image();
kontakt.src = "/grafiken/top-kontakt.gif";
}

function imgOn(imgNr, imgName) {

if (document.images && version=="1") {
document.images[imgNr].src = eval(imgName + "akt.src");
}
}

function imgOff(imgNr, imgName) {
if (document.images && version=="1") {
document.images[imgNr].src = eval(imgName + ".src");
}
}