// progressArea.setPreferredSize(new Dimension(300, 300));
ButtonBarBuilder bb = new ButtonBarBuilder();
bb.addGlue();
bb.addGridded(okButton);
bb.addRelatedGap();
bb.addGridded(cancelButton);
bb.addGlue();
JPanel bbPanel = bb.getPanel();
bbPanel.setBorder(BorderFactory.createEmptyBorder(0, 3, 3, 3));
getContentPane().add(panel, BorderLayout.CENTER);