> I understand what you are trying to explain. I disconnect database during backup process. I use vb6 for my application. Can you pl provide any to link to look after those services api calls?

You can use API Guide from old IB6 Docs, for example.

http://www.firebirdsql.org/index.php?op=doc#category_9

But, as you work in VB6, it will be not easy to use C-style API.
If you know C++ you can create ActiveX component for use in VB6 which will wrap Services API.

Regards,
Vlad