Mi appare quest'errore se provo a lanciare il .jar da me creato:

codice:
01/09/09 15:54:13 [0x0-0x5e05e].com.apple.Safari[2000] java.lang.NoClassDefFoundError: org/jdesktop/layout/GroupLayout$Group 
01/09/09 15:54:13 [0x0-0x5e05e].com.apple.Safari[2000]  at java.lang.Class.getDeclaredConstructors0(Native Method) 
01/09/09 15:54:13 [0x0-0x5e05e].com.apple.Safari[2000]  at java.lang.Class.privateGetDeclaredConstructors(Class.java:2357) 
01/09/09 15:54:13 [0x0-0x5e05e].com.apple.Safari[2000]  at java.lang.Class.getConstructor0(Class.java:2671) 
01/09/09 15:54:13 [0x0-0x5e05e].com.apple.Safari[2000]  at java.lang.Class.newInstance0(Class.java:321) 
01/09/09 15:54:13 [0x0-0x5e05e].com.apple.Safari[2000]  at java.lang.Class.newInstance(Class.java:303) 
01/09/09 15:54:13 [0x0-0x5e05e].com.apple.Safari[2000]  at sun.applet.AppletPanel.createApplet(AppletPanel.java:723) 
01/09/09 15:54:13 [0x0-0x5e05e].com.apple.Safari[2000]  at sun.applet.AppletPanel.createApplet(AppletPanel.java:723) 
01/09/09 15:54:13 [0x0-0x5e05e].com.apple.Safari[2000]  at sun.plugin.AppletViewer.createApplet(AppletViewer.java:1870) 
01/09/09 15:54:13 [0x0-0x5e05e].com.apple.Safari[2000]  at sun.applet.AppletPanel.runLoader(AppletPanel.java:652) 
01/09/09 15:54:13 [0x0-0x5e05e].com.apple.Safari[2000]  at sun.applet.AppletPanel.run(AppletPanel.java:326) 
01/09/09 15:54:13 [0x0-0x5e05e].com.apple.Safari[2000]  at java.lang.Thread.run(Thread.java:613)