how to set modal to JFrame

[Winanjaya]

I have JFrame and needs to be set modal ..
my below codes already made jf as modal .. but jf doesnot have the contents of FrmSerial..

what I missed?

JFrame jf = new FrmSerial();
JDialog jd = new JDialog(jf);
jd.setModal(true);
jd.setDefaultCloseOperation(JFrame.HIDE_ON_CLOSE);
jd.setLocationByPlatform(false);
jd.setLocation(location);
jd.pack();
jd.setVisible(true);