Questions:

Virtuous Shaikh, may Allaah grant you success; if the Jinn speaks at the end of the ruqyah, should I ask him about the magic and who did it?

Answer: No, no do not ask him about the unseen and the magic. Tell him, ‘’Fear Allaah, get out of this person; fear Allaah and do not transgress against the Muslims’’. Advise him, (but) as for asking him to inform you about things, this is not permissible–this is seeking aid and assistance from the Jinn. Yes.

[source:http://www.sahab.net/forums/index.php?showtopic=137049]