melist', uri:uri, database_name:database_name, 
                                    collection_name:collection_name}));
                        ask.onreadystatechange = () => {if (ask.readyState === ask.DONE && ask.status === 200 && req_id === req_count) {
                            var json_ask = JSON.parse(ask.responseText);
                            document.getElementById("coll_stats").innerHTML = "La collection contient " + json_ask.count + " éléments.";
                            if (json_ask.co