Netbeans java

Below is an error I get when I compile the attached program I have written.  I have not looked at the code for a few weeks as I had a question about a problem in the code and the advice I followed produced the error below.  I get the error when I try to run the program from Netbeans.  I am using Netbeans to write the program.  I have absolutely no idea how to get back where I was.  Before following the instructions, which I don't remember everything was working.  I was simply trying to add another function.  Any ideas anyone?

run:
Exception in thread "main" javax.persistence.PersistenceException: No Persistence provider for EntityManager named null:  The following providers:
oracle.toplink.essentials.PersistenceProvider
oracle.toplink.essentials.ejb.cmp3.EntityManagerFactoryProvider
Returned null to createEntityManagerFactory.

      at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:154)
      at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:83)
      at diyjdj.DiyDjMain.initComponents(DiyDjMain.java:779)
      at diyjdj.DiyDjMain.<init>(DiyDjMain.java:747)
      at diyjdj.Main.main(Main.java:19)
Java Result: 1
BUILD SUCCESSFUL (total time: 1 second)


I have no idea what is going on in line 779.  The source code is attached.  Thanks!
diy-dj.java