// Macintosh
var cssFile = '/sales/css/mac.css';
if (navigator.userAgent.indexOf('Mac') >= 0) {
document.write('<link rel="stylesheet" href="'+cssFile+'">');
}

// Windows
else if (navigator.userAgent.indexOf('Win') >= 0) {
var cssFile = '/sales/css/win.css';
document.write('<link rel="stylesheet" href="'+cssFile+'">');
}