public void addEntry() {
        if (isOnline) {
            System.out.println("Input date");
            BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
            String date = null;
            try {
                date = br.readLine();
            } catch (IOException e) {
                System.out.println("IO error!");
                System.exit(1);
            }
            System.out.println("Input time");
            String time = null;
            try {
                time = br.readLine();
            } catch (IOException e) {
                System.out.println("IO error!");
                System.exit(1);
            }
            System.out.println("Input duration");
            String duration = null;
            try {
                duration = br.readLine();
            } catch (IOException e) {
                System.out.println("IO error!");
                System.exit(1);
            }
            System.out.println("Input header (must be unique)");
            String header = null;
            try {
                header = br.readLine();
            } catch (IOException e) {
                System.out.println("IO error!");
                System.exit(1);
            }
            System.out.println("Input comment");
            String comment = null;
            try {
                comment = br.readLine();
            } catch (IOException e) {
                System.out.println("IO error!");
                System.exit(1);
            }
            CalendarEntry entry =
                    new CalendarEntry(date, time, duration, header, comment);
            entry.writeToFile();
            //1. code for reading an entry from standard input and   ... done!
            //2. creating an object CalendarEntry    ....done!
            //3. Write to file an entry.              ...done!
            //4. send a message to all active nodes about adding Entry
            //activeNodes.add(firstActiveNode);
            for (String s:activeNodes) {
                addOverRPC(s, entry.makeString());
            }
        }   else {
            System.out.println("Node is offline! Operation is not allowed");
            }

    }