private JList courseList() {
   JList result = new JList((ListModel) _plan.getSemester(_year, _semester));
   result.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
   result.setCellRenderer(_planViewCellRenderer);
   result.addListSelectionListener(
       new ListSelectionListener() {
         public void valueChanged(ListSelectionEvent e) {
           if (_courseList.getSelectedIndex() > -1) {
             _planViewPanel.courseSelected(
                 (Course) _courseList.getModel().getElementAt(_courseList.getSelectedIndex()),
                 _year,
                 _semester);
             //				_planViewPanel.setSelectedSemester(_year, _semester);
           }
         }
       });
   return result;
 }
 public void setSelected(boolean isSelected) {
   _button.setEnabled(!isSelected);
   if (!isSelected) _courseList.clearSelection();
 }