var bMouseOver = true;
 
browserName = navigator.appName;
browserVersion = parseInt (navigator.appVersion);
if (browserName == "Microsoft Internet Explorer"  && browserVersion < 4)
{
	bMouseOver = false;
}
function  img_act(imgName) {
	if (bMouseOver) {		
		imgOn = eval(imgName + "on.src");
		document [imgName].src = imgOn;
	}
}

function img_inact(imgName) {
	if (bMouseOver)	{
		imgOff = eval(imgName + "off.src");
		document [imgName].src = imgOff;
	}
}