var apOS = navigator.userAgent;

if(apOS.indexOf("Win") >= 0){
	userOS = "Win";
}else if(apOS.indexOf("Mac") >= 0){
    userOS = "Mac";
}else{
	userOS = "Win";
}

if(userOS == "Win"){
	if(document.layers) {
		document.write('<link rel="stylesheet" type="text/css" href="./common/mac_nn.css">') ;
		document.close();
	}else{
		document.write('<link rel="stylesheet" type="text/css" href="./common/win_ie.css">') ;
		document.close();
	}
}else if(userOS == "Mac"){
	if(document.layers) {
		document.write('<link rel="stylesheet" type="text/css" href="./common/mac_nn.css">') ;
		document.close();
	}else{
		document.write('<link rel="stylesheet" type="text/css" href="./common/mac_ie.css">') ;
		document.close();
	}
}