Code

function retrieveMessages(groupid, callback){
            getAllMembers(groupid, function(allmembers){
                 var json = {
                        "name": "Vizualise",
                        "data": {
                          "$area": 4,
                          "$dim": 4,
                          "$color": "#001eff"
                        }
                    };

                    w=0;
                    z=0;
                    json.children = [];
                for (var i=0, l = allmembers.length; i<l; i++) // l = allmembers.length
                {
                FB.api(
                {
                method: 'fql.query',
                query: 'SELECT actor_id, source_id, message FROM stream WHERE message != "" AND actor_id !=' + allmembers[i] + ' AND actor_id IN (' + allmembers + ') AND source_id =' + allmembers[i] + ' limit 1000'
                }, function(resp){
                if(resp[0] != undefined)
                {
                    //console.log(" ");
                    //console.log("TO:" + resp[0].source_id);
                    json.children[z] = {
                        id: 'node'+ w,
                        name: resp[0].source_id,
                        data: {
                            $area : 2,
                            $dim : 2,
                            $color: '#111'

                        }
                    };
                    w++;
                    json.children[z].children = [];
                    x=0;
                for (var j=0, k=resp.length; j<k; j++)
                {
                    if(resp[j].message != undefined)
                    {

                    json.children[z].children[x] = {
                        id: 'node'+ w,
                        name: resp[j].actor_id,
                        data: {
                            $area : 10,
                            $dim : 10,
                            $color: '#000'

                        }
                    };
                    w++;

                    //console.log("FROM: " + resp[j].actor_id);
                    y=0;
                    json.children[z].children[x].children = [];

                    for(m=0, n=resp.length; m<n;m++)
                    {
                        if(resp[j].actor_id == resp[m].actor_id)
                        {
                            //console.log("MESSAGE: " + resp[m].message);
                            json.children[z].children[x].children[y] = {
                                id:'node' + w,
                                name: resp[m].message,
                                data: {
                                    $area : 10,
                                    $dim : 10,
                                    $color: '#111'

                                }

                            }

                            w++;
                            y++;

                            delete resp[m].message;
                        }
                    }

                     x++;
                    }

                }
                z++;
                }
                });
                }
                //console.log(json);
               /* setTimeout(function(){
                callback(json);
                    },500);*/
                callback(json);
                });
        }