else if (source == dialogDeleteSubtree) {
if (DialogBoxUIFactory.isYesEvent(event)) {
// remember the parent of the subtree being deleted
CatalogEntry parent = currentCatalogEntry.getParent();
// delete the subtree!!!
cm.deleteCatalogEntry(currentCatalogEntry);
// display the parent
historyStack.remove(historyStack.size() - 1);
updateContent(ureq.getIdentity(), parent, historyStack.indexOf(parent));
updateToolAccessRights(ureq, parent, historyStack.indexOf(parent));
fireEvent(ureq, Event.CHANGED_EVENT);