function setCookie(name, value, days) {
    var expireDate = new Date()
    //set "expstring" to either future or past date, to set or delete cookie, respectively
    var expstring=(typeof days!="undefined")? expireDate.setDate(expireDate.getDate()+parseInt(days)) : expireDate.setDate(expireDate.getDate()-5)
    document.cookie = name+"="+value+"; expires="+expireDate.toGMTString()+"; path=/";
}