function createCookie(name, value, days, domain, path) {
  var expires = '';
  if (days) {
    var d = new Date();
    d.setTime(d.getTime() + (days*24*60*60*1000));
    expires = '; expires=' + d.toGMTString();
  }
  domain = domain ? '; domain=' + domain : '';
  path = '; path=' + (path ? path : '/');
  document.cookie = name + '=' + value + expires + path + domain;
}

function readCookie(name) {
  var n = name + '=';
  var cookies = document.cookie.split(';');
  for (var i = 0; i < cookies.length; i++) {
    var c = cookies[i].replace(/^\s+/, '');
    if (c.indexOf(n) == 0) {
      return c.substring(n.length);
    }
  }
  return null;
}

function eraseCookie(name, domain, path) {
  setCookie(name, '', -1, domain, path);
}