* Move selected fields from "used" to "not used"
*/
private void moveToNotUsed() {
// get the values from the "not use" list and convert to sorted set
ListModel notUseColsModel = notUseColsList.getModel();
SortedSet<String> notUseColsSet = new TreeSet<String>();
for (int i=0; i<notUseColsModel.getSize(); i++)
notUseColsSet.add((String)notUseColsModel.getElementAt(i));
// get the values from the "use" list
ListModel useColsModel = useColsList.getModel();
// create an empty set for the "use" list
SortedSet<Object> useColsSet = new TreeSet<Object>();
// for each element in the "use" set, if selected then add to "not use",
// otherwise add to new "use" set
for (int i=0; i<useColsModel.getSize(); i++) {
String colName = (String)useColsModel.getElementAt(i);
if (useColsList.isSelectedIndex(i))
notUseColsSet.add(colName);
else useColsSet.add(colName);
}