@Override public void actionPerformed(ActionEvent event) { if (event.getSource() == boutonJouer) { String s = (String) JOptionPane.showInputDialog( this, "Veuillez entrer votre nom", "Nouvelle partie", JOptionPane.PLAIN_MESSAGE, null, null, "Dupont"); // If a string was returned, say so. if ((s != null) && (s.length() > 0)) { Joueur.getInstance().setUsername(s); } else return; this.setVisible(false); mainWindow.setVisible(true); } else if (event.getSource() == boutonAbout) { textWindow.setVisible(true); } }