function getCookie(key)
{ key = key.toLowerCase();
  var pairs = document.cookie.split(';'), pair, i;
  for(i=0; i<pairs.length; i++)
  { pair = pairs[i].split('=');
    if(unescape(pair[0].replace(/^\s+|\s+$/g, "").toLowerCase())==key)
      return unescape(pair[1]);
  }
  return null;
}

function setCookie(key, value, exp)
{ key = key.toLowerCase();
  var time = new Date();
  if(exp==null) time.setDate(time.getDate()+30);
  else if(typeof(exp)=="number") time.setDate(time.getDate()+exp);
  else if(typeof(exp)=="string") time = new Date(exp);
  else time = exp;
  document.cookie = escape(key)+"="+escape(value)+"; path=/; expires="+
                    time.toGMTString();
}

function setPersistentCookie(key, value)
{ setCookie(key, value, new Date("1/1/2038"));
}

function expireCookie(key) { setCookie(key, "", new Date("1/1/1970")); }