 network.on("dragEnd", function (params) {
        params.event = "[original event]";
        document.getElementById('eventSpan').innerHTML = '<h2>dragEnd event:</h2>' + JSON.stringify(params, null, 4);
    });
    network.on("zoom", function (params) {
        document.getElementById('eventSpan').innerHTML = '<h2>zoom event:</h2>' + JSON.stringify(params, null, 4);
    });
    network.on("showPopup", function (params) {
        document.getElementById('eventSpan').innerHTML = '<h2>showPopup event: </h2>' 