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 getRandomStyleSheet() {
  var i, a;
  while (true)
  {
    for(i=0; (a = document.getElementsByTagName("link")[i]); i++) {
      if(a.getAttribute("rel").indexOf("style") != -1
         && a.getAttribute("title")
         && (Math.random()*3) < 1
         ) return a.getAttribute("title");
    }
  }
  
  //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 : getRandomStyleSheet();
  setActiveStyleSheet(title);
  createCookie("style", title, 365);
}

window.onunload = function(e) {
  var title = getActiveStyleSheet();
  createCookie("style", title, 365);
}

var cookie = readCookie("style");
var title = cookie ? cookie : getRandomStyleSheet();
createCookie("style", title, 365);
setActiveStyleSheet(title);