JOptionPane not working outside contractor.

Question

Hello
I have a problem with my JOptionPane�s. If I use them within the constructor, it works fine with the correct decoration, format and graphic. I have a couple in methods within the same class and when I try and use a JOptionPane with these they do not display correctly. (no �ok� button, detonation or body text�only the title)
Does anyone have any idea why this is and any ways around it?
Thanks,
Harold

Answer 1

Sorry about that guys, I wrote this post after a very late night of programming:
Here is the code:
import javax.swing.JOptionPane;
import ...
public class GeneticAlgorithm extends JFrame implements ActionListener, WindowListener, ItemListener
     public GeneticAlgorithm()
         super("GeneticAlgorithm v3");
          //Sort screen size and position
          Dimension screenSize =      Toolkit.getDefaultToolkit().getScreenSize();
          if (screenSize.width < 1024 && screenSize.height < 768)
               String resError = "Please note that this applecation is desgined to run\n with the resolution of 1024x768";
               //WORKS FINE
               JOptionPane.showMessageDialog(null, resError, "Screen Resolution Error", JOptionPane.ERROR_MESSAGE);
               setSize(1024, 768);
     ...other Methods
     private boolean verifyStartParameters()
          boolean startSim = true;
          if (populationSize == 0)
               //DOES NOT WORK
               JOptionPane.showMessageDialog(null, "ERROR: Population Size = 0", "Population Size Error", JOptionPane.ERROR_MESSAGE);
               startSim = false;
          if (generationSize == 0)
               //DOES NOT WORK
               JOptionPane.showMessageDialog(null, "ERROR: Generation Size = 0", "Generation Size Error", JOptionPane.ERROR_MESSAGE);
               startSim = false;
          //DOES NOT WORK
          if (mutationRate == 0) {JOptionPane.showMessageDialog(null, "WARNING: Mutation Rate = 0", "Mutation Rate Warning", JOptionPane.WARNING_MESSAGE);}
          return startSim;
}