function setActiveStyleSheet(title) {
  var i, a, main;
  for(i=0; (a = document.getElementsByTagName("link")[i]); i++) {
    if(a.getAttribute("rel").indexOf("style") != -1 && a.getAttribute("title")) {
      a.disabled = true;
      if(a.getAttribute("title") == title) a.disabled = false;
    }
  }
}

function getActiveStyleSheet() {
  var i, a;
  for(i=0; (a = document.getElementsByTagName("link")[i]); i++) {
    if(a.getAttribute("rel").indexOf("style") != -1 && a.getAttribute("title") && !a.disabled) return a.getAttribute("title");
  }
  return null;
}

function getPreferredStyleSheet() {
  var i, a;
  for(i=0; (a = document.getElementsByTagName("link")[i]); i++) {
    if(a.getAttribute("rel").indexOf("style") != -1
       && a.getAttribute("rel").indexOf("alt") == -1
       && a.getAttribute("title")
       ) return a.getAttribute("title");
  }
  return null;
}

function createCookie(name,value,days) {
  if (days) {
    var date = new Date();
    date.setTime(date.getTime()+(days*24*60*60*1000));
    var expires = "; expires="+date.toGMTString();
  }
  else expires = "";
  document.cookie = name+"="+value+expires+"; path=/";
}

function readCookie(name) {
  var nameEQ = name + "=";
  var ca = document.cookie.split(';');
  for(var i=0;i < ca.length;i++) {
    var c = ca[i];
    while (c.charAt(0)==' ') c = c.substring(1,c.length);
    if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length,c.length);
  }
  return null;
}

window.onload = function(e) {
  var cookie = readCookie("style");
  var title = cookie ? cookie : getPreferredStyleSheet();
  setActiveStyleSheet(title);
}

window.onunload = function(e) {
  var title = getActiveStyleSheet();
  createCookie("style", title, 365);
}

var cookie = readCookie("style");
var title = cookie ? cookie : getPreferredStyleSheet();
setActiveStyleSheet(title);


//　Macintosh           　->  MacOS
//　Windows95/98/NT/2000/XP  ->　Windows
//　UNIX                  ->　UNIX
function getOSType()
{
    var uAgent  = navigator.userAgent.toUpperCase();
    if (uAgent.indexOf("MAC") >= 0) return "MacOS";
    if (uAgent.indexOf("WIN") >= 0) return "Windows";
    if (uAgent.indexOf("X11") >= 0) return "UNIX";
    return "";
}
//　Netscape Navigator ->  Netscape
//　Internet Explorer  ->　Explorer
//　Safari  ->　Safari
//　Opera  ->　Opera
function getBrowserName()
{
    var aName  = navigator.appName.toUpperCase();
    var uName = navigator.userAgent.toUpperCase();
    if (uName.indexOf("SAFARI") >= 0)  return "Safari";
    if (uName.indexOf("OPERA") >= 0)  return "Opera";
    if (aName.indexOf("NETSCAPE") >= 0)  return "Netscape";
    if (aName.indexOf("MICROSOFT") >= 0) return "Explorer";
    return "";
}
function getBrowserVersion()
{
	var browser = getBrowserName();
	var version = 0;
	var s = 0;
	var e = 0;
	var appVer  = navigator.appVersion;
	var uName  = navigator.userAgent.toUpperCase();
	if (browser == "Safari")
	{
		version = eval(appVer.substring(0,3)) - 4;
	}
	if (browser == "Opera")
	{
		s = uName.indexOf("OPERA ",0) + 6;
		e = uName.indexOf(" ",s);
		version = eval(uName.substring(s,e));
	}
	if (browser == "Netscape")
	{
		s = appVer.indexOf(" ",0);
		version = eval(appVer.substring(0,s));
		if (version >= 5) version++;
	}
	if (browser == "Explorer")
	{
		appVer  = navigator.userAgent;
		s = appVer.indexOf("MSIE ",0) + 5;
		e = appVer.indexOf(";",s);
		version = eval(appVer.substring(s,e));
	}
	return version;
}


os      = getOSType();
if (os == "Windows") {
document.write('<link rel="alternate stylesheet" type="text/css" href="/interweb/share/css/common_s.css" title="small" />');
document.write('<link rel="stylesheet" type="text/css"  href="/interweb/share/css/common.css" title="default" />');
document.write('<link rel="alternate stylesheet" type="text/css" href="/interweb/share/css/common_l.css" title="large" />');
}
if (os == "MacOS") {
document.write('<link rel="alternate stylesheet" type="text/css" href="/interweb/share/css/common_s.css" title="small" />');
document.write('<link rel="stylesheet" type="text/css"  href="/interweb/share/css/common.css" title="default" />');
document.write('<link rel="alternate stylesheet" type="text/css" href="/interweb/share/css/common_l.css" title="large" />');
}
