//set typeface
var Win=(navigator.userAgent.indexOf("Win",0)!=-1);
var Mac=(navigator.userAgent.indexOf("Mac",0)!=-1);
if(Mac) {
document.write('<LINK rel="stylesheet" href="./css/mac.css" type="text/css">');
}else if(Win) {
document.write('<LINK rel="stylesheet" href="./css/win.css" type="text/css">');
}