/**
* Creates and returns a Container containin the buttons. The buttons
* are created by calling <code>getButtons</code>.
*/
protected Container createButtonArea() {
JPanel bottom = new JPanel(new ExtButtonAreaLayout(true, 6));
bottom.setBorder(UIManager.getBorder("OptionPane.buttonAreaBorder"));
addButtonComponents(bottom, getButtons(), getInitialValueIndex());
return bottom;
}