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);