browserName = navigator.appName;
browserVer = parseInt(navigator.appVersion);

ns3up = (browserName == "Netscape" && browserVer >= 3);
ie4up = (browserName.indexOf("Microsoft") >= 0 && browserVer >= 4);

function doPic(imgName) {
if (ns3up || ie4up) {
imgOn = ("" + imgName);
document.getElementById("mainpic").src = imgOn;
}
}



function log_out()
{
        ht = document.getElementsByTagName("html");
        ht[0].style.filter = "progid:DXImageTransform.Microsoft.BasicImage(grayscale=1)";
        if (confirm('Möchtest Du dich wirklich abmelden?'))
        {
                return true;
        }
        else
        {
                ht[0].style.filter = "";
                return false;
        }
}