private int getPreferredHeight() {
		int maxHeight = 0;
		for (int i=0, count=getComponentCount(); i<count; i++) {
			Component component = getComponent(i);
			Rectangle r = component.getBounds();
			int height = r.y + r.height;
			if (height > maxHeight) {
				maxHeight = height;
			}
		}
		maxHeight += ((FlowLayout) getLayout()).getVgap();
		return maxHeight;
	}