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();
}