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 >= 4.0)
	{
	roll = 'true';
	}
else
	{
	roll = 'false';
	}

function m_on(img){
	if (roll == 'true')
		{
		document.images[img].src = 'image1/aniy.gif';
		}
}
function m_off(img){
	if (roll == 'true')
		{
		document.images[img].src = 'image1/anin.gif';
		}
}