browser = (((navigator.appName == "Netscape") && (parseInt(navigator.appVersion) >= 3 )) || ((navigator.appName == "Microsoft Internet Explorer") && (parseInt(navigator.appVersion) >= 4 )))

if (browser)

{

Img1off = new Image(123, 30);
Img1off.src = "images/back1.gif";
Img1on = new Image(123, 30);
Img1on.src = "images/back2.gif";


}

function loadimage(imageName, imgObjName)
{
    if (browser) 
    {
        document.images[imageName].src = eval(imgObjName + ".src");
        return true;
    }
}