function ReadCookie(cookieName) {
  var theCookie=''+document.cookie;
  var ind=theCookie.indexOf(cookieName);
  if (ind==-1 || cookieName=='') return '';
  var ind1=theCookie.indexOf(';',ind);
  if (ind1==-1) ind1=theCookie.length;
  return unescape(theCookie.substring(ind+cookieName.length+1,ind1));
}