function SetCookie(c_name, value, expiredays) {
    var exdate = new Date();
    exdate.setDate(exdate.getDate() + expiredays);
    document.cookie = c_name + "=" + escape(value) +
((expiredays == null) ? "" : ";expires=" + exdate.toUTCString());
}

function GetCookie(c_name) {
    if (document.cookie.length > 0) {
        c_start = document.cookie.indexOf(c_name + "=");
        if (c_start != -1) {
            c_start = c_start + c_name.length + 1;
            c_end = document.cookie.indexOf(";", c_start);
            if (c_end == -1) c_end = document.cookie.length;
            return unescape(document.cookie.substring(c_start, c_end));
        }
    }
    return "";
}

function OptIn() {
    SetCookie("TDID", NewGuid(), 90);
    return;
}

function OptOut() {
    SetCookie("TDID", NullGuid(), 1825);
    return;
}


function S4() {
    return (((1 + Math.random()) * 0x10000) | 0).toString(16).substring(1);
}

function NewGuid() {
    return (S4() + S4() + "-" + S4() + "-" + S4() + "-" + S4() + "-" + S4() + S4() + S4());
}

function NullGuid(){
    return "00000000-0000-0000-0000-000000000000";
}