function changefontsize(size) {
  setActiveStyleSheet(size);
  changeImage(size);
}

function changeImage(size) {
  var imageHTML = document.getElementById("text-resize");
  imageHTML.innerHTML = imageHTML.innerHTML.replace(/_on/,"_off");

  var imageChange = document.getElementById(size);
  if (imageChange == null || imageChange == "") {
    imageChange = document.getElementById("medium");
  }
  imageChange.innerHTML = imageChange.innerHTML.replace(/_off/,"_on");
}

function setActiveStyleSheet(title) {
  var a = document.getElementById('container');
  switch (title)
  {
    case "small":
      a.style.fontSize = "85%";
      break;
    case "medium":
      a.style.fontSize = "100%";
      break;
    case "large":
      a.style.fontSize = "120%";
      break;
    case "xlarge":
      a.style.fontSize = "140%";
      break;
  }
}

function getActiveStyleSheet() {
  var a = document.getElementById('container').style.fontSize;
  switch (a)
  {
    case "85%":
      return "small";
      break;
    case "100%":
      return "medium";
      break;
    case "120%":
      return "large";
      break;
    case "140%":
      return "xlarge";
      break;
  }
}

function getPreferredStyleSheet() {
  return ("medium");
}

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);
  changeImage(title);
}

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

//var cookie = readCookie("style");
//var title = cookie ? cookie : getPreferredStyleSheet();
//if (title == 'null') {
//  title = getPreferredStyleSheet();
//}

//setActiveStyleSheet(title);