JAVA確認ダイアログ

import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JFrame;
import javax.swing.JOptionPane;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.JTextField;


public class Border extends JFrame implements ActionListener{
	JTextArea jTextArea;
	JTextField jTextField;
	Border(){
		super("  ");
		
		jTextField = new JTextField(12);
		add(jTextField,BorderLayout.NORTH);
		jTextField.addActionListener(this);
		
		jTextArea = new JTextArea();
		add(new JScrollPane(jTextArea),BorderLayout.CENTER);
		
		setBounds(200, 200, 300, 400);
		setVisible(true);
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
	}

	public static void main(String[] args) {
		Border border = new Border();

	}
	public void actionPerformed(ActionEvent e){
		String string = jTextField.getText();
		int n = JOptionPane.showConfirmDialog(this,"      ","     ",
                                      JOptionPane.YES_NO_OPTION );
		 if(n==JOptionPane.YES_OPTION) {  
	         jTextArea.append("
"+string);
	         jTextField.setText("");
	      }  
	      else if(n==JOptionPane.NO_OPTION) { 
	         jTextField.setText(null);
	      }  
	}

}