JavaScript 브라우저 체크 (OS 체크는 보너스)

function getNavigatorInfoStr()
{
    var name = navigator.appName, ver = navigator.appVersion,
        ver_int = parseInt(navigator.appVersion), ua = navigator.userAgent, infostr;
    if(name == "Microsoft Internet Explorer")
    {
        if(ver.indexOf("MSIE 3.0") != -1) return "Internet Explorer 3.0x";
        if(ver_int != 4) return "Internet Explorer " + ver.substring(0, ver.indexOf(" "));
 
        var real_ver = parseInt(ua.substring(ua.indexOf("MSIE ") + 5));
        if(real_ver >= 7) infostr = "Windows Internet Explorer ";
        else infostr = "Microsoft Internet Explorer ";
 
        if(ua.indexOf("MSIE 5.5") != -1) return infostr + "5.5";
        else return infostr + real_ver + ".x";
 
        return "Internet Explorer";
    }
    else if(name == "Netscape")
    {
        if(parseInt(ua.substring(8, 8)) <= 4)
          return "Netscape " + ver.substring(0, ver.indexOf(" "));
        else if(ua.lastIndexOf(" ") < ua.lastIndexOf("/"))
          return ua.substring(ua.lastIndexOf(" "));
        else return "Netscape";
    }
    else return name;
}
 
function getOSInfoStr()
{
    var ua = navigator.userAgent;
 
    if(ua.indexOf("NT 6.0") != -1) return "Windows Vista/Server 2008";
    else if(ua.indexOf("NT 5.2") != -1) return "Windows Server 2003";
    else if(ua.indexOf("NT 5.1") != -1) return "Windows XP";
    else if(ua.indexOf("NT 5.0") != -1) return "Windows 2000";
    else if(ua.indexOf("NT") != -1) return "Windows NT";
    else if(ua.indexOf("9x 4.90") != -1) return "Windows Me";
    else if(ua.indexOf("98") != -1) return "Windows 98";
    else if(ua.indexOf("95") != -1) return "Windows 95";
    else if(ua.indexOf("Win16") != -1) return "Windows 3.x";
    else if(ua.indexOf("Windows") != -1) return "Windows";
    else if(ua.indexOf("Linux") != -1) return "Linux";
    else if(ua.indexOf("Macintosh") != -1) return "Macintosh";
    else return "";
}