import java.applet.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public abstract class Boll_AI extends Applet implements ActionListener
{
Label lb;
TextField in,out;
public void init()
{
lb = new Label("计算器");
in = new TextField(12);
out = new TextField(24);
add(lb);
add(in);
add(out);
in.addActionListener((ActionListener) this);
}
public void ActionPerformed(ActionEvent e){
out.setText(in.getText() + "=");
}
}