With this function i want to insert data into my firebase database:

function insertDaten(titel) {
    var ref = firebase.database().ref();
    ref.on("value", function (snapshot) {
        var json_elemente = snapshot.val().notes;
        var keys = Object.keys(json_elemente);
        var count = Math.max.apply(null, keys) + 1;

        firebase.database().ref("notes/" + count).set({
            id: parseInt(count) + 1,
            text: "",
            titel: titel,
            bild: ""
    });
  });
}

but everytime i run it, it seems to loop and create as many datasets as it can before the program shuts down. i've tried to just add a return; but that doesn't seem to work either.