try {
openTransaction();
Query query = pm.newQuery(MType.class, "name == typeName");
query.declareParameters("java.lang.String typeName");
query.setUnique(true);
MType type = (MType) query.execute(typeName.trim());
pm.retrieve(type);
pm.deletePersistent(type);
commited = commitTransaction();
success = true;
} catch (JDOObjectNotFoundException e) {