Thanks for the nice comments, i think i was very lucky.
I haven't seen the frog since i put him/her in the tank, thought he had a very stressful day so i would leave him in peace. So no, he hasn't eaten for me yet.
He/she is about 2inches long, i was told he was this years hatchling & looks quite plump, i'm looking forward to finding him tonight to feed, hope he eats.

Marg.