var nb_max_font = 5;

function mid(String, Start, Length)
{
   if (String == null) return (false);
   if (Start > String.length) return '';
   if (Length == null || Length.length == 0) return (false);
   return String.substr((Start - 1), Length);
}

function changerStyleSheet(action) {
  var title = getActiveStyleSheet();
  if (title == null || title.length != 5) title = 'font3';
  var noFont = parseInt(mid(title,5,1));
  var noFont = action == '+' ? 1 + noFont : -1 + noFont;
  if (noFont >= 1 && noFont <= nb_max_font) setActiveStyleSheet("font" + noFont);
}

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;
}

if (window.addEventListener)
window.addEventListener("load", onLoadStyleSheet, false)
else if (window.attachEvent)
window.attachEvent("onload", onLoadStyleSheet)

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

function onLoadStyleSheet() {
  var cookie = readCookie("styleside");
  var title = cookie ? cookie : getPreferredStyleSheet();
  if (title == 'font1')
  	 title = 'font3';
  setActiveStyleSheet(title);
}