import java.util.*;
import javax.swing.*;

class JOptionPaneDemo extends JComponentWithEvents {  

  public void start() {
    alert("This is a test message!");
    String result = readString("Enter a string!");
    alert("You entered: " + result);
  }
  
  public void alert(String msg) {
    JOptionPane.showMessageDialog(null, msg, "alert", JOptionPane.INFORMATION_MESSAGE);
  }
  
  public String readString(String prompt) {
    return JOptionPane.showInputDialog(prompt);
  }

  public static void main(String[] args) { launch(500, 500); }
}