Reverting change of jComboBox Master/Detail form

[pee.tee]

Hello,

I've two problems with reverting changes of jComboBox in standard Master/Detail form.

1.
I have method:

private void jComboBox2ItemStateChanged(java.awt.event.ItemEvent evt) {
if (!<some testing>) {
this.jComboBox2.setSelectedItem(z.getIdMj());
}
}

which sets (if testings failed) value of jComboBox2 back to previous value from database.

Unfortunately both values (in master table and in combobox) remains with new value. How can I change value back to value from database?

2.
I have in Detail section of standard Master/Detail Form jComboBox and I need actualize content of jComboBox items by button which reads content from database. But every tries to refresh content failed. Have you any suggestions?

Thanks in advance