import java.awt.*;
import java.awt.event.*;
import java.applet.*;


public class HelloWorldApp extends Frame implements
                                                 ActionListener {
 private Image im ;

		Button      button = new Button("Exit");
	    Panel       panel = new Panel();
	    Label       label = new Label("Hello World!");

 public void start(String args) {
        setLayout(new FlowLayout(FlowLayout.CENTER));
		panel.setLayout(new FlowLayout(FlowLayout.CENTER,2,2));
		panel.add(button);
		panel.add(label);
		add("North", panel);

		button.addActionListener(this);

        validate();
}
   public void actionPerformed(ActionEvent event) {

                String str = event.getActionCommand();

                if (str == "Exit")

				System.exit(0);

    }

	public static void main (String args[]){
	   	HelloWorldApp    testApp = new HelloWorldApp();
		testApp.start("a");
		testApp.setSize(240, 280);
		testApp.validate();
        testApp.show();
	}
}