JAVA - mitol fagy a delete gomb utan a program?

program kod a delete gombra:

[link]

Ha kitorlok egy elemet az adatbazisbol lefagy a program. Azt akarnam ha kitorlok valmit akkor utana mukodjon a next,prev gomb...(a torles vegbe megy,ha lekapcsolom es ujbol elinditom a programot az elem kitorlodott)

forras: [link]

error:

Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException

at Employees.Workers.btnDeleteRecordActionPerformed(Workers.java:801)

at Employees.Workers.access$600(Workers.java:28)

at Employees.Workers$7.actionPerformed(Workers.java:268)

workes.java:80

stmt = con.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,

ResultSet.CONCUR_UPDATABLE);

Workers.java:28

public class Workers extends javax.swing.JFrame {

Workers.java:268

btnDeleteRecordActionPerformed(evt);