function SetCookie(cookieName,cookieValue,nDays) {
  var today = new Date();
  var expire = new Date();
  if (nDays==null || nDays==0)
    nDays=1;

  expire.setTime(today.getTime() + 3600000*24*nDays);
  document.cookie = cookieName+"="+escape(cookieValue) + ";expires="+expire.toGMTString();
}