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 showsub(num)
{
 if (document.getElementById('sub'+num).style.display=='block')
	{
	 document.getElementById('sub'+num).style.display='none';
		document.images['p'+num].src='http://www.tehnoton.net/menu/close.png';
	}
	else
	{
	 document.getElementById('sub'+num).style.display='block';
		document.images['p'+num].src='http://www.tehnoton.net/menu/open.png';
	}
}