Makin GUI for input and output

Question

This is simple code for my Comp Science class at school, but I keep getting "Exception in thread "main" java.lang.NoClassDefFoundError: TrivialApplication"
and im tryin to figure out what i did heres my code:
import java.awt.*;
import java.awt.event.*;
import java.io.*;
import javax.swing.*;
public class Hypotenuse {
          double side1, side2, hypotenuse;
          String Fside1, Fside2;
     public Component components()
     final JTextArea text = new JTextArea();
     final JTextField InputText1 = new JTextField();
     final JTextField InputText2 = new JTextField();
     JButton button = new JButton(" OK ");
     button.setMnemonic(KeyEvent.VK_ENTER);
     button.addActionListener(new ActionListener(){
          public void actionPerformed(ActionEvent e)
               Fside1 = InputText1.getText();
               Fside2 = InputText2.getText();
     JPanel InOutField = new JPanel();
     InOutField.setBorder(BorderFactory.createEmptyBorder(30,30,30,30));
     InOutField.setLayout(new GridLayout(0, 1));
          InOutField.add(text);
          InOutField.add(InputText1);
          InOutField.add(InputText2);
          InOutField.add(button);
          return InOutField;
     public static void main(String Args[]) throws IOException
         try
          UIManager.setLookAndFeel(
               UIManager.getCrossPlatformLookAndFeelClassName());
         catch (Exception e)
          JFrame InOutFrame = new JFrame("Hypotenuse");
          Hypotenuse app = new Hypotenuse();
          Component contents = app.components();
          InOutFrame.getContentPane().add(contents, BorderLayout.CENTER);
          InOutFrame.addWindowListener(new WindowAdapter()
               { public void windowCloasing(WindowEvent e)
                    { System.exit(0);
          InOutFrame.pack();
          InOutFrame.setVisible(true);
}

Answer 1

It compiles OK for me, but it doesn't close properly, unless I change this
public void windowCloasing(WindowEvent e)
to this
public void windowClosing(WindowEvent e)