an = navigator.appName;
	av = navigator.appVersion;
	ua = navigator.userAgent;

	iev = 4; 
	nsv = 4; 

	if(ua.indexOf("Win") != -1) //WindowsOS
	{
		if((an.indexOf("Microsoft") >= 0) && (av.charAt(0) >= iev))
		{
			document.write("<link rel='stylesheet' href='css/win/win_ie.css' type='text/css'>"); 
		}
		else if((an.indexOf("Netscape") >= 0) && (av.charAt(0) >= nsv))
		{
			document.write("<link rel='stylesheet' href='css/win/win_ns.css' type='text/css'>"); 
		}
	}
	else if(ua.indexOf("Mac") != -1)//MacOS...
	{
		if((an.indexOf("Microsoft") >= 0) && (av.charAt(0) >= iev))
		{
			document.write("<link rel='stylesheet' href='css/mac/mac_ie.css' type='text/css'>"); 
		}
		else if((an.indexOf("Netscape") >= 0) && (av.charAt(0) >= nsv))
		{
			document.write("<link rel='stylesheet' href='css/mac/mac_ns.css' type='text/css'>"); 
		}
	}