import java.awt.*;
import java.awt.event.*;
class ButtonExample
	extends WindowAdapter
		implements ActionListener {
	Frame f;
	Button b;
	TextField tf;
	int tag = 0;

	public static void main(String args[]) {
		ButtonExample be = new ButtonExample( );
		be.go( );
	}

	public void go( ) {
		f = new Frame("ButtonExample");
		b = new Button("Sample");
		b.addActionListener(this);
		f.add(b,"South");

		tf = new TextField( );
		f.add(tf,"Center");

		f.addWindowListener(this);
		f.setSize(300,150);
		f.setVisible(true);
	}

	//  實現ActionListener接口中的actionPerformed( )方法
	public void actionPerformed(ActionEvent e) {
		String s1 = "You have pressed the Button!";
		String s2 = "You do another time!";

		if (tag==0) {
			tf.setText(s1);
			tag = 1;
		}	else	{
			tf.setText(s2);
			tag = 0;
		}
	}


	//  覆蓋WindowAdapter類中的windowClosing( )方法
	public void windowClosing(WindowEvent e){
	//  結束程序運行
		System.exit(0);
		}
}