How to set focus in the parent window after a JOptionPane pop up ?

Question

I am not able to set the focus back to a JTextField in the parent window after poping up a JOptionpane.showMessageDialog(). I tried requestfocus(),requestFocusInWindow etc......but not working. The code is given below.
if ((encryptor.encrypt(password)).equals(configuredPasswd)) {
                    validPassword = true;
               } else {
                    JOptionPane.showMessageDialog(saveUI,"The password entered is not correct.");
                    saveUI.getPasswdField().setText("");
saveUI.getPasswdField().requestFocus();
Sometimes the focus is coming to the JTextField.Sometimes it appears for a moment and then dissappears.Please give a solution

Answer 1

see if this makes a difference
if((encryptor.encrypt(password)).equals(configuredPasswd))
  validPassword = true;
else
  JOptionPane.showMessageDialog(saveUI,"The password entered is not correct.");
  ActionListener al = new ActionListener(){
    public void actionPerformed(ActionEvent ae){
      saveUI.getPasswdField().setText("");
      saveUI.getPasswdField().requestFocusInWindow();}};
  javax.swing.Timer timer = new javax.swing.Timer(100,al);
  timer.setRepeats(false);
  timer.start();
}