function fontsizeup() {
  active = getActiveStyleSheet();
  switch (active) {
    case 'A' : 
      setActiveStyleSheet('A+');
      break;
    case 'A+' : 
      setActiveStyleSheet('A++');
      break;
    case 'A++' :
	  setActiveStyleSheet('A+++');
      break;
	case 'A+++' :
      break;
    default :
      setActiveStyleSheet(getPreferredStyleSheet());
      break;
  }
}

function fontsizedown() {
  active = getActiveStyleSheet();
  switch (active) {
    case 'A+++' : 
      setActiveStyleSheet('A++');
      break;
    case 'A++' : 
      setActiveStyleSheet('A+');
      break;
    case 'A+' : 
      setActiveStyleSheet('A');
      break;
    case 'A' : 
      break;
    default :
      setActiveStyleSheet(getPreferredStyleSheet());
      break;
  }
}

function getPreferredStyleSheet() {
  return ('A');
}

/**
 * Set active style-sheet.
 */
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;
    }
  }
}

/**
 * Get active style-sheet.
 */
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;
}

window.onload = function() {
  var title = readCookie("style");
  if(title == null) {
     title = getPreferredStyleSheet();
  }
  setActiveStyleSheet(title); 
}

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

/*
var title = readCookie("style");
if(title == null) {
   title = getPreferredStyleSheet();
}
setActiveStyleSheet(title); 
*/