createcookie

var createCookie = function createCookie(name, value, days) {
    var expires;
    if (days) {
        var date = new Date();
        date.setTime(date.getTime()+(days*24*60*60*1000));
        expires = "; expires="+date.toGMTString();
    }
    else {
        expires = "";
    }
    document.cookie = name+"="+value+expires+"; path=/";
}