I'm having real issues getting some buttons to resize. the app is to be on touch screen, so they need to be big enough to be prodded with fat fingers...

//The constructor...
public TotalDialog(float total) {
topPanel = new JPanel();
topPanel.setLayout(new BoxLayout(topPanel,BoxLayout.Y_AXIS));
bottomPanel = new JPanel(new GridLayout(1,4));
ftotal = total;
addWidgets();
mainPanel = new JPanel();
mainPanel.add(topPanel);
topPanel.add(bottomPanel);
System.out.print("Total: "+total+"\n");
JDialog.setDefaultLookAndFeelDecorated(true);
JDialog tdFrame = new JDialog(ownerFrame,true);
tdFrame.setDefaultCloseOperation(JFrame.DO_NOTHING_ON_CLOSE);
tdFrame.setContentPane(mainPanel);
tdFrame.setSize(400,300);
tdFrame.setVisible(true);
}

private void addWidgets() {
java.text.DecimalFormat formatter = new java.text.DecimalFormat("#.00");
JLabel lMessage = new JLabel("Please enter the amount tendered:");
lMessage.setAlignmentX(Component.CENTER_ALIGNMENT);
lMessage.setFont(lMessage.getFont().deriveFont(Font.BOLD, 18));
topPanel.add(lMessage);
JLabel lOwing = new JLabel(""+formatter.format(ftotal)+" Owing");
lOwing.setAlignmentX(Component.CENTER_ALIGNMENT);
topPanel.add(lOwing);
lOwing.setFont(lOwing.getFont().deriveFont(Font.BOLD, 18));
JTextArea tInput = new JTextArea(formatter.format(ftotal));
Font myFont = new Font(tInput.getFont().getFontName(),tInput.getFont().getStyle(),tInput.getFont().getSize() );
myFont = myFont.deriveFont((float)72);
tInput.setFont(myFont);
topPanel.add(tInput);
JButton bCash = new JButton("Cash");
JButton bCard = new JButton("Card");
JButton bCheque = new JButton("Cheque");
JButton bVoucher = new JButton("Voucher");
bCash.setSize(200,200);
bCard.setSize(100,100);
bCheque.setSize(100,100);
bVoucher.setSize(100,100);
bottomPanel.add(bCash);
bottomPanel.add(bCard);
bottomPanel.add(bCheque);
bottomPanel.add(bVoucher);
}

So, bCash JButton should be twice the h & w as the rest, but it's not. What's going on?