Is it possible to edit or delete a PM not yet read by recipient?

[hcwhcw]

Is it possible to either edit or delete a PM I sent that has not yet been read by recipient? TIA.

Edited to add: If the answer to this question is already covered in some FAQ or other thread, please link me up. I looked and didn't find. Thanks again.

[shelleyf]

I don't think you can do that. Maybe someone else knows for sure. I tried that but didn't work.