因为写这个程序，我电脑上现在有N多不能关闭的小程序窗口，除了重新启动，我应该怎样关闭它们？


package applet;
import java.awt.*;
import java.awt.event.*;
public class MyTextArea extends Frame implements TextListener {
static Frame fr=new Frame("My new window!Superb!");
TextArea ta1,ta2;
public MyTextArea(){
setBounds(0,0,200,160);
String str1="Come on,boy!";
String str2="What a sunny day today!";
ta1=new TextArea(str1,10,6,TextArea.SCROLLBARS_VERTICAL_ONLY);
ta2=new TextArea(str2,10,6,TextArea.SCROLLBARS_HORIZONTAL_ONLY);
setLayout(new FlowLayout(FlowLayout.LEFT));
ta1.addTextListener(this);
ta2.setEditable(false);
add(ta1);
add(ta2);
setVisible(true);
}

public void textValueChanged(TextEvent e){
ta2.setText(ta1.getText());
}
public static void main(String args[]){
new MyTextArea();

fr.addWindowListener(new WindowAdapter(){
public void windowClosing(WindowEvent e){
System.exit(0);
}
}
);

}

}

frame.addWindowListener(new WindowAdapter(){
public void windowClosing(WindowEvent e){
System.exit(0);
}
});