browser_name = navigator.appName;
browser_version = parseFloat(navigator.appVersion); 
if (browser_name == "Netscape" && browser_version >= 3.0) { 
	roll = 'true';
} else if (browser_name == "Microsoft Internet Explorer" && browser_version >= 3.0) { 
	roll = 'true'; 
} else { 
	roll = 'false'; 
}

function mo(img,ref) { 
	if (roll == 'true') { 
		document.images[img].src = ref; 
	} 
}
function mt(img,ref)  { 
	if (roll == 'true') { 
		document.images[img].src = ref; 
	} 
}
function msover(img,ref) { 
	if (roll == 'true') { 
		document.images[img].src = ref; 
	} 
}
function msout(img,ref)  { 
	if (roll == 'true') { 
		document.images[img].src = ref; 
	} 
}