browser_name = navigator.appName;
browser_version = parseFloat(navigator.appVersion);

if (browser_name == "Netscape" && browser_version >= 3.0)
{ rollover = 'true'; }
else if (browser_name == "Microsoft Internet Explorer" && browser_version >= 4.0)
{ rollover = 'true'; }
else { rollover = 'false'; }

function mOver(img,ref) { if (rollover == 'true') { document.images[img].src = ref; } }
function mOut(img,ref) { if (rollover == 'true') { document.images[img].src = ref; } }