function setFontSize(size) {
  if (!document.styleSheets) return;
  var theRules = new Array();
  if (document.styleSheets[0].cssRules)
    theRules = document.styleSheets[0].cssRules
  else if (document.styleSheets[0].rules)
    theRules = document.styleSheets[0].rules
  else return;
  if (size) {
    theRules[0].style.fontSize = size;
  }
}

function getActiveFontSize() {
  if (!document.styleSheets) return;
  var theRules = new Array();
  if (document.styleSheets[0].cssRules)
    theRules = document.styleSheets[0].cssRules
  else if (document.styleSheets[0].rules)
    theRules = document.styleSheets[0].rules
  else return;
  return theRules[0].style.fontSize;
}

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("fontSize");
  setFontSize(cookie);
}

window.onunload = function(e) {
  var size = getActiveFontSize();
  createCookie("fontSize", size, 365);
}

var cookie = readCookie("fontSize");
setFontSize(cookie);