void removeExhibit() {
   if (exhibitNameList.getModel().getSize() > 1) {
     peer.getLoader().removeExhibit((String) exhibitNameList.getSelectedValue());
     exhibitNameList.setSelectionInterval(0, 0);
     peer.makeChange();
     exhibitNameModel.notifyChange();
   }
 }
 void addExhibit() {
   String newName = JOptionPane.showInputDialog("Name of new exhibit:");
   if (newName != null && ZipManager.exhibitNamePattern.matcher(newName).matches()) {
     String newContentName = JOptionPane.showInputDialog("Name of first new content:");
     if (newContentName != null && ZipManager.localPathPattern.matcher(newContentName).matches()) {
       ExhibitInfo newE = new ExhibitInfo(newName, 0, 0, null, null);
       newE.setContent(newContentName, peer.getOriginalFiles()[0]);
       peer.getLoader().getExhibits().add(newE);
       exhibitNameModel.notifyChange();
       contentListModel.notifyChange();
       peer.makeChange();
     } else {
       System.out.println("Invalid tag name " + newContentName);
     }
   } else {
     System.out.println("Invalid exhibit name " + newName);
   }
 }