var OSType = null;
var browserType = null;

function getOS(){
  if(navigator.userAgent){
    if( navigator.userAgent.indexOf("Windows") != -1 ){
      OSType = "Windows";
    }
    else if( navigator.userAgent.indexOf("Mac") != -1 ){
      OSType = "Macintosh";
    }
    else{
      OSType = "Others";
    }
  }
  else{
    OSType = "Others";
  }
}

function getBrowser(){
  if(navigator.userAgent){
    if( navigator.userAgent.indexOf("MSIE") != -1 ){
      // MSIE
      browserType = "MSIE";
    }
    else if(navigator.userAgent.indexOf("Safari") != -1){
      // Safari
      browserType = "Safari";
    }
    else if(navigator.userAgent.indexOf("Gecko/") != -1){
      // Gecko Browser ie. Netscape 6, 7 Mozilla 1.x etc...
      browserType = "Gecko";
    }
    else if(navigator.userAgent.indexOf("Mozilla") != -1){
      // maybe Netscape 4.xx
      browserType = "Mozilla";
    }
    else{
      browserType = "Others";
    }
  }
  else{
    browserType = "Others";
  }
}

function printCSSTag(){
  if(OSType == "Windows" && browserType == "MSIE"){
    document.writeln('<link rel="stylesheet" type="text/css" href="css/win_ie.css">');
  }
  else if(OSType == "Windows" && browserType == "Gecko"){
    document.writeln('<link rel="stylesheet" type="text/css" href="css/win_ns.css">');
  }
  else if(OSType == "Windows" && browserType == "Mozilla"){
    document.writeln('<link rel="stylesheet" type="text/css" href="css/win_ns.css">');
  }
  else if(OSType == "Macintosh" && browserType == "MSIE"){
    document.writeln('<link rel="stylesheet" type="text/css" href="css/mac_ie.css">');
  }
  else if(OSType == "Macintosh" && browserType == "Gecko"){
    document.writeln('<link rel="stylesheet" type="text/css" href="css/mac_ns.css">');
  }
  else if(OSType == "Macintosh" && browserType == "Mozilla"){
    document.writeln('<link rel="stylesheet" type="text/css" href="css/mac_ns.css">');
  }
  else if(OSType == "Macintosh" && browserType == "Safari"){
    document.writeln('<link rel="stylesheet" type="text/css" href="css/mac_ns.css">');
  }
  else{
    document.writeln('<link rel="stylesheet" type="text/css" href="css/win_ns.css">');
  }
}

getOS();
getBrowser();