*/
public void event(UserRequest ureq, Component source, Event event) {
if (source == previewButton) { // those must be links
Controller tunnelRunCtr;
if (config.getBooleanSafe(TUConfigForm.CONFIG_IFRAME)) {
tunnelRunCtr = new IframeTunnelController(ureq, getWindowControl(), config);
} else {
tunnelRunCtr = new TURunController(getWindowControl(), config, ureq, courseNode, PreviewConfigHelper.getPreviewCourseEnvironment(true, true, course));
}
if (previewLayoutCtr != null) previewLayoutCtr.dispose();
// preview layout: only center column (col3) used