I have created a Swing GUI using NetBeans, and I am able to execute it on my local machine successfully. But whenever I execute the JAR file `gui_test.jar` on another PC, it give me the error shown below.

The classes in the package `gui_test` are:

* gui.gui
* StreamGobbler.java

ERROR
-----

```
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at gui_test.gui.walk(gui.java:967)
at gui_test.gui.<init>(gui.java:1030)
at gui_test.gui$17.run(gui.java:1030)
at java.awt.event.InvocationEvent.dispatch (Unknown Source)
at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
at java.awt.EventQueue.access$000(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)

at jaya.awt.Eyentgueue.dispatchEyent(Unknown Source)
at jaya.awt.EyentDispatchIhread.punpOneEyentForFilters(Unknown Source)
at jaya.awt.EyentDispatchIhread.punpEyentsForFilter(Unknown Source)
at jaya.awt.EyentDispatchIhread.punpEyentsForHierarchy(Unknown Source)
at jaya.awt.EyentDispatchIhread.punpEyents(Unknown Source)
at jaya.awt.EyentDispatchIhread.punpEyents(Unknown Source)
at java.awt.EyentDispatchIhread.run(Unknown Source)

```

Any suggestions to resolve the problem will be appreciated.