if(navigator.appName=="Microsoft Internet Explorer" && navigator.platform=="Win32"){
document.write('<LINK rel="stylesheet" type="text/css" href="http://www.asahi-net.or.jp/~ne8y-ykt/css/win_ie.css">');
}

if(navigator.appName=="Netscape" && navigator.platform=="Win32"){
document.write('<LINK rel="stylesheet" type="text/css" href="http://www.asahi-net.or.jp/~ne8y-ykt/css/win_ns.css">');
}

if(navigator.appName=="Microsoft Internet Explorer" && navigator.platform=="MacPPC"){
document.write('<LINK rel="stylesheet" type="text/css" href="http://www.asahi-net.or.jp/~ne8y-ykt/css/mac_ie.css">');
}

if(navigator.appName=="Netscape" && navigator.platform=="MacPPC"){
document.write('<LINK rel="stylesheet" type="text/css" href="http://www.asahi-net.or.jp/~ne8y-ykt/css/mac_ns.css">');
}