title: About ComboBox in JOptionPane using dialog
body: <p>I would like to get a dialog box using joptionpane as a Combobox where I want to accept the values of day, month and year. I want all these in a single dialog box. What I've is this: </p>
  
  <pre><code> String[] date= {"1","2","3","4","5","6","7","8","9","10","11","12","13","14","15","16","17","18","19","20","21","22","23","24","25","26","27","28","29","30","31"};
      String[] month= {"1","2","3","4","5","6","7","8","9","10","11","12"};
      String[] year={"2016","2017","2018","2019","2020"};
      JComboBox jcd = new JComboBox(date);
      JComboBox jcm = new JComboBox(date);
      JComboBox jcy = new JComboBox(date);
        jcd.setEditable(true);
        jcm.setEditable(true);
        jcy.setEditable(true);
      JOptionPane.showMessageDialog( null, jcd, "Date", JOptionPane.QUESTION_MESSAGE);
      JOptionPane.showMessageDialog( null, jcm, "Month", JOptionPane.QUESTION_MESSAGE);
      JOptionPane.showMessageDialog( null, jcy, "Year", JOptionPane.QUESTION_MESSAGE);
  
      int resd=(int) jcd.getSelectedItem();
      int resm=(int) jcd.getSelectedItem();
      int resy=(int) jcd.getSelectedItem();
  </code></pre>
  
  <p>Here the issue is that I'm getting 3 dialog boxes one after another for entering values where I want to make it as a single dialog box which have multiple comboboxes.</p>