import javax.swing.*;

public class DialogBox
{
    public static void main2(String [] args)
    {
        JOptionPane myin = new JOptionPane();
        String instructor = myin.showInputDialog("Enter instructor's name");
        System.out.println(instructor);
        System.exit(0);  // kills off UI thread
    }
    
    public static void main()
    {
        String inString;
        double radius;
        double area;
        JOptionPane inBox = new JOptionPane();
        JOptionPane outBox = new JOptionPane();
        
        inString = inBox.showInputDialog("Enter Radius");
        radius = Double.parseDouble(inString);
        area = Math.PI * radius * radius;
        
        outBox.showMessageDialog(
            null, // select default parent frame
            "Radius: " + radius + ", Area: " + area
        );
        
        /*
        outBox.showMessageDialog(
            null, // select default parent frame 
            String.format("Radius: %.2f, area: %.2f", radius, area)
        );
        */
        
        System.exit(0);  // kills off UI thread        
    }
}