Внешний вид и ощущение морского стекла

Я написал простой тестовый класс, чтобы протестировать функции внешнего вида Seaglass http://seaglass.googlecode.com. и я получаю исключение «класс nimbus не найден».

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


 public class asd {

    private static void createWindow() throws ClassNotFoundException, InstantiationException, IllegalAccessException, UnsupportedLookAndFeelException {

       //Create and set up the window. 
       JFrame frame = new JFrame("Simple GUI");
       frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 

       JLabel textLabel = new JLabel("I'm a label in the window",SwingConstants.CENTER); 
       textLabel.setPreferredSize(new Dimension(300, 100)); 
       frame.getContentPane().add(textLabel, BorderLayout.CENTER); 

       //Display the window. 
       frame.setLocationRelativeTo(null); 
       frame.pack();
       frame.setVisible(true);
               }

    public static void main(String[] args) {
             try {
                UIManager.setLookAndFeel("com.seaglasslookandfeel.SeaGlassLookAndFeel");
                createWindow();
            } catch (ClassNotFoundException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (InstantiationException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (IllegalAccessException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (UnsupportedLookAndFeelException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }



    }
 } 

Исключение

Exception in thread "main" java.lang.NoClassDefFoundError: com/sun/java/swing/plaf/nimbus/NimbusLookAndFeel
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(Unknown Source)
at java.security.SecureClassLoader.defineClass(Unknown Source)
at java.net.URLClassLoader.defineClass(Unknown Source)
at java.net.URLClassLoader.access$000(Unknown Source)
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClassInternal(Unknown Source)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Unknown Source)
at javax.swing.SwingUtilities.loadSystemClass(Unknown Source)
at javax.swing.UIManager.setLookAndFeel(Unknown Source)
at asd.main(asd.java:31)