在java中 如何使按钮点击后 弹出一个新的对话框？

[code="java"]
import java.awt.Color;
import javax.swing.JFrame;
import java.awt.Font;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.FileInputStream;
import java.io.File;
import java.io.InputStream;
import javax.swing.Icon;
import javax.swing.JLabel;
import javax.swing.ImageIcon;

import javax.swing.JTextField;
import javax.swing.JButton;
import javax.swing.JTextArea;

public class TTest
{
public static void main(String[] args)
{

    final JFrame frame = new JFrame("闹钟");


    JTextField time = new JTextField(30);
    JLabel timeLab = new JLabel("定时时间设定(请输入数字) ：");
    JTextArea event = new JTextArea(3, 10);
    // JTextField event = new JTextField(80);
    JLabel eventLab = new JLabel("事件提醒设定 ：");
    JButton but = new JButton("确 定");

    but.addActionListener(new ActionListener()
    {
        public void actionPerformed(ActionEvent e)
        {
            JFrame jf = new JFrameTest();
            frame.setVisible(false);
            jf.setVisible(true);
        }
    });
    but.setBounds(300, 120, 80, 20);
    String picPath = "D:" + File.separator + "0852193.jpg";
    File file = new File(picPath);
    InputStream input = null;
    byte b[] = new byte[(int) file.length()];
    try
    {
        input = new FileInputStream(file);
        input.read(b);
        input.close();
    }
    catch (Exception e)
    {
        e.printStackTrace();

    }

    Icon icon = new ImageIcon(b);
    JLabel lab = null;
    lab = new JLabel("", JLabel.LEFT);
    Font fnt = new Font("Serief", Font.ITALIC + Font.BOLD, 28);
    lab.setFont(fnt);
    lab.setBackground(Color.YELLOW);
    lab.setForeground(Color.RED);
    timeLab.setBounds(200, 20, 170, 20);
    eventLab.setBounds(200, 50, 100, 20);
    time.setBounds(380, 20, 150, 25);
    event.setBounds(310, 50, 220, 50);
    frame.add(timeLab);
    frame.add(time);
    frame.add(eventLab);
    frame.add(event);
    frame.add(but);
    frame.add(lab);
    frame.setSize(600, 200);
    frame.setBackground(Color.WHITE);
    frame.setLocation(300, 200);
    frame.setLocation(300, 200);
    frame.setVisible(true);

}

}

class JFrameTest extends JFrame
{
public JFrameTest()
{
init();
}

public void init()
{
    this.setSize(300, 300);
    this.setTitle("弹出框");

// this.setVisible(true);
}
}
[/code]