// JavaScript Document
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;
   }
 }
}
<!--Primeiro vamos ver qual o style sheet que o usuário preferiu usar: -->
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 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;
}