error implementation callback in nodejs and mongodb
<p>this is my code</p>

<pre><code>Event.find({ start_date: { $lte: new Date() }, end_date: { $gte: new Date() }, isDeleted: false }).limit(10).sort({ created_at: 'desc' }).populate('moderator').exec(function (err, events) {
    if (err) throw err;

    var response = [];
    events.forEach(function (ev) {

        var moderatorName = ev.moderator.facebook.name;

        User.find({ currentEvent: ev._id }).exec(function (err, users) {

            callback(null, users);
        });


        if (ev.isFanPage)
            moderatorName = ev.fanPageName;

        response.push({ eventId: ev._id, title: ev.name, description: ev.description, thumb: ev.thumb, moderator: moderatorName, moderatorFbId: ev.moderator.facebook.id, countPicture: ev.numberOfUploadedImages, countVideo: users });
    });

    next(response);
});
</code></pre>

<p>I want to insert the list of users of the event in field contvideo the my response.  </p>

<p>I used bad callback ?</p>

<p><strong>UPDATE 16/03/2016</strong></p>

<p>My solution is call function callback in function the find user the event.</p>

<p>my function find user the event.</p>

<pre><code>exports.getEventUsers = function (id, next, callback) {
console.log("id evento " + id);
User.find({ currentEvent: id }).exec(function (err, users) {
    if (err)
        res.send("ERROR");

   callback(users);


});};
</code></pre>

<p>my proces event is </p>

<pre><code>Event.find({ isDeleted: false }).limit(10).sort({ created_at: 'desc' }).populate('moderator').exec(function (err, events) {
    if (err) throw err;

    var response = [];
    var namearray = [];
    var total = events.length;
    console.log("cant evento" + total);
    events.forEach(function (ev) {

        var moderatorName = ev.moderator.facebook.name;
        var usuario = [];
        if (ev.isFanPage)
            moderatorName = ev.fanPageName;

        console.log("evento id " + ev._id);

        exports.getEventUsers(ev._id,next,function(retorno) {
            total--;
            console.log("evento id " + ev._id);
            console.log("cantidad elementos evento " + response.length);
            response.push({ eventId: ev._id, title: ev.name, description: ev.description, thumb: ev.thumb, moderator: moderatorName, moderatorFbId: ev.moderator.facebook.id, countPicture: ev.numberOfUploadedImages, participantes: retorno.length });

            if(total == 0)
            next(response);

        });

    });

    console.log("termino el proceso");
});
</code></pre>