搞了一天了，还是没有弄出来，请各位看看，先谢谢了。
package Firstpanel;
import java.awt.*; //import java.awt.event.ActionEvent;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener; //import java.awt.event.KeyEvent;
//import java.awt.event.WindowAdapter;
//import java.awt.event.WindowEvent;
import javax.swing.*;
import javax.swing.JFrame;
import javax.swing.table.*;
@SuppressWarnings("serial")
public class MainWindow extends JFrame implements ActionListener {
// private static final Component JPanel = null;
private JTabbedPane tabbedPane;
private JLabel label1, label2, label3;
private JPanel panel1,panel2,panel3;
private JButton button1, button2, button3, button4, button5, button6,
button7, button8;
private JTextField cTxt1;
private JComboBox c1, c2, c3, c4, c5;
//private JScrollPane j1, j2, j3;
public MainWindow() {
super("管理界面");
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (Exception e) {
// TODO: handle exception
}
setSize(700, 500);
setResizable(false);
centerJFrame();
Container container = getContentPane();
tabbedPane = new JTabbedPane();
panel1 = new JPanel();
panel1.setBackground(Color.cyan);
panel2 = new JPanel();
panel3 =
