function getOSType()
{
    var uAgent  = navigator.userAgent.toUpperCase();
    if (uAgent.indexOf("MAC") >= 0) return "MacOS";
    if (uAgent.indexOf("WIN") >= 0) return "Windows";
    return "";
}
os      = getOSType();
if (os == "MacOS")   dirName = "cmn/css/font_mac.css";
if (os == "Windows") dirName = "cmn/css/font_win.css";
document.write("<link rel='stylesheet' href='"+dirName+"' type='text/css'>");