Trouble with JDialog

Hi!
This one compiles just fine, but here only the JLabel is visible cant get
"add(new NyttDyr(),BorderLayout.SOUTH);" to work... Whats wrong??

public NyHareDialog(JFrame foreldre){
super(foreldre,"Registrer ny hare",true);
add(new JLabel("Tast inn informasjon om ny hare:"),BorderLayout.NORTH);
add(new NyttDyr(),BorderLayout.SOUTH);
setLocationRelativeTo(null);
//setSize(300,300);
pack();
}

Here is rest of the code..

import java.util.*;
import java.io.*;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.sql.*;

class DyreRegister extends JFrame{
public static void main(String[] args) {
ForeldreVindu meny = new ForeldreVindu();
meny.setSize(1000,300);
meny.setLocationRelativeTo(null);
meny.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE );
meny.setVisible(true);
}//Main
} //Programklasse

class NyHareDialog extends JDialog{
private Kontroll kontroll = new Kontroll();
private boolean ok;

public NyHareDialog(JFrame foreldre){
super(foreldre,"Registrer ny hare",true);
add(new JLabel("Tast inn informasjon om ny hare: "),BorderLayout.NORTH);
add(new NyttDyr(),BorderLayout.SOUTH);
setLocationRelativeTo(null);
//setSize(300,300);
pack();
}

private class KnappeLytterDialog implements ActionListener{
public void actionPerformed(ActionEvent hendelse){
String kommando = hendelse.getActionCommand();
ok = kommando.equals("OK");
setVisible(false);
}//Metode
}//Klassen KnappeLytterDialog

private class NyttDyr extends JPanel{
public void NyttDyr(){

KnappeLytterDialog knappelytter = new KnappeLytterDialog();
JButton okKnapp, avbrytKnapp;
JPanel p1,p2,p3,p4,p5,p6;
JLabel l1,l2,l3,l4,l5;
JTextField t1,t2,t3,t4,t5;

setLayout(new GridLayout(6,2));

p1 = new JPanel();
add(p1);
l1 = new JLabel("Kjønn: ");
p1.add(l1);
t1 = new JTextField(10);
p1.add(t1);
String kjønn = t1.getText();

p2 = new JPanel();
add(p2);
l2 = new JLabel("Lengde: ");
p2.add(l2);
t2 = new JTextField(10);
p2.add(t2);
String lengdeT = t2.getText();
Double lengde = Double.parseDouble(lengdeT);

p3 = new JPanel();
add(p3);
l3 = new JLabel("Vekt: ");
p3.add(l3);
t3 = new JTextField(10);
p3.add(t3);
String vektT = t3.getText();
Double vekt = Double.parseDouble(vektT);

p4 = new JPanel();
add(p4);
l4 = new JLabel("Sted: ");
p4.add(l4);
t4 = new JTextField(10);
p4.add(t4);
String sted = t4.getText();

p5 = new JPanel();
add(p5);
l5 = new JLabel("Dato: ");
p5.add(l5);
t5 = new JTextField(10);
p5.add(t5);
String dato = t5.getText();

p6 = new JPanel();
add(p6);
avbrytKnapp = new JButton("Avbryt");
p6.add(avbrytKnapp);
avbrytKnapp.addActionListener(knappelytter);

okKnapp = new JButton("OK");
p6.add(okKnapp);
okKnapp.addActionListener(knappelytter);

}//Metode
}//Klassen

public boolean visDialog(){
setVisible(true);
return ok;
}

}//Klassen NyHareDialog

class ForeldreVindu extends JFrame{
private NyHareDialog nyhareboks = new NyHareDialog(this);

public ForeldreVindu(){
KnappeLytterForeldre knappelytter = new KnappeLytterForeldre();
JPanel p1,p2;
JButton b1,b2,b3,b4,b5;
setLayout(new GridLayout(2,1));
p1 = new JPanel();
add(p1); //Legger til i rutenettet til vindu
p2 = new JPanel();
add(p2); //Legger til i rutenettet til vindu
p1.setLayout(new GridLayout(1,5,5,5));

b1 = new JButton("Ny hare");
p1.add(b1);
b1.addActionListener(knappelytter);

b2 = new JButton("Ny gaupe");
p1.add(b2);
b2.addActionListener(knappelytter);

b3 = new JButton("Gjenfangst hare");
p1.add(b3);
b3.addActionListener(knappelytter);

b4 = new JButton("Gjenfangst gaupe");
p1.add(b4);
b4.addActionListener(knappelytter);

b5 = new JButton("Utskrift");
p1.add(b5);
b5.addActionListener(knappelytter);

pack();
}//PUBLIC ForeldreVindu

private class KnappeLytterForeldre implements ActionListener{
public void actionPerformed(ActionEvent hendelse){
if(nyhareboks.visDialog()){
System.out.println("Ok trykket.");

}else{
System.out.println("Avbryt trykket.");
}//else
}//metode
}//klassen KnappeLytterForeldre