var isNav;

 if (navigator.userAgent.indexOf("inux") != -1)
   {
       //alert("linux");
       document.write ('<LINK REL=StyleSheet href="fontl.css" TYPE=text/css>');
       isNav=true;
   }
else if ((navigator.userAgent.indexOf("inux") != 1) && (navigator.appName == 'Netscape'))
   { 
    isNav = true;
    document.write('<LINK REL=StyleSheet href="fontn.css" TYPE=text/css> ');
   }
 else if((navigator.userAgent.indexOf("inux") != 1) && (navigator.appName != 'Netscape'))
   {
    isNav = false;
    document.write('<LINK REL=StyleSheet href="font.css" TYPE=text/css> ');
   }