/* Cookie functions to determining screen size for gradient */
/* Code adapted from w3schools.com website: http://www.w3schools.com/js/js_cookies.asp */
function cookieOperations(width, height)
{
  checkCookie('learGradW', width);
  checkCookie('learGradH', height);
}

function getCookie(c_name, value)
{
  if (document.cookie.length > 0)
  {
    c_start = document.cookie.indexOf(c_name + "=");
    if (c_start != -1)
    { 
      c_start = c_start + c_name.length + 1; 
      c_end = document.cookie.indexOf(";", c_start);
      if (c_end == -1) c_end = document.cookie.length;
      return unescape(document.cookie.substring(c_start, c_end));
    } 
  }
  return "";
}

function setCookie(c_name, value, expiredays)
{
  var exdate = new Date();
  exdate.setDate(exdate.getDate() + expiredays);
  document.cookie = c_name + "=" + escape(value)+
  ((expiredays==null) ? "" : ";expires="+exdate.toGMTString());
}

function checkCookie(c_name, value)
{
  storedValue = getCookie(c_name);
  if (storedValue == value) { return; }
  else  { setCookie(c_name, value, 365); }
}