The IPersistMessage::IsDirty method checks the form for changes made since the last save.
See IPersistMessage : IUnknown.
HRESULT IsDirty();
None
Form viewers call the IPersistMessage::IsDirty method to determine whether the message has unsaved data.
For more information, see the documentation for the following OLE methods in the OLE Programmer's Reference:
IPersistStorage::IsDirty
IPersistStream::IsDirty
IPersistFile::IsDirty