import javax.swing.*;
import java.awt.event.*;

public class distance extends JFrame
{
      private JPanel panel;
      private JLabel messageLabel;
      private JTextField textField;
      private JButton calcButton;
      private final int window_width = 310;
      private final int window_height = 210;

public distance()
      {
         setTitle("Distance after seconds");
         setSize(window_width,window_height);
         setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
         buildPanel();
         add(panel);
         setVisible(true);
      }

private void buildPanel()
{
      messageLabel = new JLabel("Enter the amount of seconds");
      textField = new JTextField(10);
      calcButton = new JButton("Calculate");
      calcButton.addActionListener(new CalcButtonListener());
      panel = new JPanel();
      panel.add(messageLabel);
      panel.add(textField);
      panel.add(calcButton);
}

private class CalcButtonListener implements ActionListener
{
   public void actionPerformed(ActionEvent e)
   {
      String input;
      double seconds;
      double dist;
      input = textField.getText();
      seconds = Double.parseDouble(input);
      dist = 16*(seconds*seconds);
      JOptionPane.showMessageDialog(null,"The object will fall "+dist+" distance after "+seconds+" seconds.");
   }
}

public static void main(String[] args)
{
   new distance();
}
}