Destroys a notification connection that had been previously set up.
HRESULT DUnadvise(
  DWORD dwConnection  //Connection to remove
);
 This methods destroys a notification created with a call to the IDataObject::DAdvise method.
If the advisory connection being deleted was initially set up by delegating the IDataObject::DAdvise call to IDataAdviseHolder::Advise, you must delegate this call to IDataAdviseHolder::Unadvise to delete it.
  Windows NT: Use version 3.1 or later.
  Windows: Use Windows 95 or later.
  Windows CE: Unsupported.
  Header: Declared in objidl.h.
IDataObject::DAdvise, IDataAdviseHolder::Unadvise