if (source == configVC) {
String command = event.getCommand();
if (command.equals(CMD_ADD)) {
// add new event to calendar
String calendarID = ureq.getParameter(PARAM_ID);
fireEvent(ureq, new KalendarGUIAddEvent(calendarID, new Date()));
} else if (command.equals(CMD_TOGGLE_DISPLAY)) {
String calendarID = ureq.getParameter(PARAM_ID);
KalendarRenderWrapper calendarWrapper = findKalendarRenderWrapper(calendarID);
KalendarConfig config = calendarWrapper.getKalendarConfig();
config.setVis(!config.isVis());