function setCookie(key, value, expiredays)
{
    var ExpireDate = new Date();

    ExpireDate.setTime(ExpireDate.getTime() + (expiredays * 24 * 3600 * 1000));
    document.cookie = key + "=" + escape(value) + 
    ((expiredays == null) ? "" : "; expires=" + ExpireDate.toGMTString() +"; path=/");
}