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;
			}
    	}
  	}
	createCookie("style", title, 365); 
} 
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;
}
//checks if cookie exists
function csearch(naam) { 
  var str = document.cookie; 
  var zstr = naam + "="; 
  var start = str.indexOf(zstr, 0); 
  if(start == -1) { 
    return false; 
  } else { 
    start += zstr.length; 
    var eind = str.indexOf(";", start); 
    if(eind == -1) eind = str.length; 
	return unescape(str.substring(start, eind)); 
  } 
}  
window.onunload = function(e) {
  	var title = getActiveStyleSheet();
  	createCookie("style", title, 365); 
} 
var cookie = readCookie("style");
var title = cookie ? cookie : getPreferredStyleSheet();
setActiveStyleSheet(title);