Ball tossed to the board, violation or not.

[bogref_jed]

On a fast break play, A1 has the ball dribbling towards the basket for a lay up shot being chase by B1, followed by A2 (about two steps behind B1). A1 thinking that B1 might block his shot, tossed the ball to the board, A2 got the ball in the air and dunked it or A2 after getting the ball landed on the floor and took the shot successfully.

Question: In FIBA Rules 1998-2002, is there any violation by A1 or A2? Kindly explain.

We will be very thankful to those who will share their knowledge of the rules or viewpoint.

Thanks,
bogref