if (navigator.platform.indexOf('Mac') > -1) {
    //mac
	document.write('<LINK HREF="http://www.dentsu-razorfish.com/en/css/style_mac.css" REL="styleSheet" TYPE="text/css">');
} else {
	//windows or unix
	if (navigator.appName.indexOf('Microsoft') > -1) {
      //explorer
		document.write('<LINK HREF="http://www.dentsu-razorfish.com/en/css/style_win_ie.css" REL="styleSheet" TYPE="text/css">');
	} else {
		//netscape
		document.write('<LINK HREF="http://www.dentsu-razorfish.com/en/css/style_win.css" REL="styleSheet" TYPE="text/css">');
	}
}