public String edit() {
   initTbgts();
   textbookBiz = textbookBizService.get(textbookBiz);
   csds = courseSeriesService.getDtos();
   slds = studyLevelService.getDtosByCourseSeries(textbookBiz.getCourseSeries());
   return SUCCESS;
 }
 public String add() {
   csds = courseSeriesService.getDtos();
   initTbgts();
   return SUCCESS;
 }