public bool deattach(IDataTableObserver observer) {
     return m_oDataTableObservers.Remove(observer);
 }
 public void attach(IDataTableObserver observer)
 {
     if (m_oDataTableObservers == null) m_oDataTableObservers = new LinkedList<IDataTableObserver>();
     m_oDataTableObservers.AddLast(observer);
 }