removeAll();
//for every alternative overlay a panel is created
for (int i = 0; i < alternativeOverlays.size(); i++) {
JPanel previewContainerPanel = new JPanel();
previewContainerPanel.setPreferredSize(new Dimension(150, 200));
String overlayName = (String) alternativeOverlays.elementAt(i);
previewPanels[i] = new PreviewPanel();
previewPanels[i].setBorder(BorderFactory.createLineBorder(Color.BLACK));
previewPanels[i].setImage(model.getImageFromDocument(model.getDocumentByName(overlayName)));
//only one can be chosen, by mouse or with tab -> radioButtons
previewRadioButtons[i] = new PreviewRadioButton(overlayName);