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

if (browserName == "Netscape" && browserVer >= 4 || browserName == "Microsoft Internet Explorer" && browserVer >= 4) version = "v4";
        else version = "v3";
             
function img_act(imgName) {
	if (version == "v4") {
		imgOn = eval(imgName + "Over.src");
        document[imgName].src = imgOn;
     }
}

function img_inact(imgName) {
	if (version == "v4") {
		imgOff = eval(imgName + "Out.src");
        document[imgName].src = imgOff;
    }
}