interaction: Object
  panning: Object
  resizing: Object
  selection: Object
  zooming: Object
    autoZoom: true
    autoZoomDuration: 500
    autoZoomSize: 0.9
    doubleClickZoom: 1.5
    fingers: true
    sensitivity: 1
    wheel: true

function graphDoubleClick(event){
            $("#nodemenu").css("display", "none");
            $("#linkmenu").css("display", "none");

            if (event.clickNode && event.shiftKey){//test the click was on a node
                    chart.addData({
                        nodes:[{
                            "id":"n"+nextId,
                            "type":"unknown",
                            "x":event.chartX,
                            "y":event.chartY,
                            "loaded":true,
                            "style":{"label":"newNode"}
                            }],
                        links:[{
                            "id":"ll"+nextId,
                             from:event.clickNode.id,
                             to:"n"+nextId,
                             "style":{"label":"unknown"}
                             }]
                    });
                    nextId += 1;
            }
            else if  (!event.clickNode && !event.clickLink && event.shiftKey){
                    chart.addData({
                        nodes:[{
                            "id":"n"+nextId,
                            "loaded":true,
                            "type":"unknown",
                            "x":event.chartX,
                            "y":event.chartY,
                            "style":{"label":"newNode"}
                            }]
                    });
                    nextId += 1;
            };

        }