Java-newbie will Dialoge zentrieren und ein schönes GUI-Design haben

public YesNoDialog(Frame owner, String msg)
{
	super(owner, "Frage");  
	Point parloc = owner.getLocation();
	setLocation(parloc.x + (290 - WIDTH/2), parloc.y + (210 -HEIGHT/2));
	setResizable(false);
		
	setLayout(new BorderLayout());
		
	add(new Label(msg), BorderLayout.CENTER);
	Panel panel = new Panel();
	panel.setLayout(new FlowLayout(FlowLayout.CENTER));
	Button button = new Button("Ja");  
	button.addActionListener(this);
	panel.add(button);
		
	button = new Button("Nein");  
	button.addActionListener(this);
	panel.add(button);
	add(panel, BorderLayout.SOUTH);
		
	pack();
}

	setLocation(parloc.x + (290 - WIDTH/2), parloc.y + (210 -HEIGHT/2));