var prefsLoaded = false;
var defaultFontSize = 12;
var currentFontSize = defaultFontSize;

function revertStyles()
{
  currentFontSize = defaultFontSize;
  changeFontSize(0);
}

function changeFontSize(sizeDifference)
{
  currentFontSize = parseInt(currentFontSize) + parseInt(sizeDifference * 3);
  if(currentFontSize > 18) currentFontSize = 18;
  if(currentFontSize < 12) currentFontSize = 12;
  setFontSize(currentFontSize);
}

function setFontSize(fontSize)
{
  var stObj = (document.getElementById) ? document.getElementById('content') : document.all('content');
  stObj.style.fontSize = fontSize + 'px';
}

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 = setUserOptions;

function setUserOptions()
{
  if(!prefsLoaded){
    cookie = readCookie("fontSize");
    currentFontSize = cookie ? cookie : defaultFontSize;
    setFontSize(currentFontSize);
    prefsLoaded = true;
  }
}

window.onunload = saveSettings;

function saveSettings()
{
  createCookie("fontSize", currentFontSize, 365);
}