var Appversion = navigator.appVersion.charAt(0);
var Appname = navigator.appName.charAt(0);

with( document ){
	if(navigator.appVersion.indexOf("Mac") > -1){
		write('<link rel="stylesheet" type="text/css" href="' + '/' + 'css/font_mac.css">');
	}else{
		write('<link rel="stylesheet" type="text/css" href="' + '/' + 'css/font.css">');
	}
}