AS3: MovieClips animation

I have something like this:

my main function has something like this:

makeSwap (firstPiece, secondPiece);

if (!findMatches())

{

     makeSwap (firstPiece, secondPiece);

}

private function makeSwap (piece1, piece2)

{

     piecesSwap(piece1, piece2);

     gridSwap(piece1, piece2);

}

So, what I want to do is something like this:

I want to animated move the position of these 2 pieces. After the move is done, I want to check if the move is Ok. If the move is Ok, the pieces remains on their positions, if not i want them to animated reverse the pieces as they were before the move.

What is happening with ENTER_FRAME, is that if the movement is Ok, the pieces are animated moved, but if the movement is not Ok, the pieces are not moved at all. They remain in the same position.

So, what I need is ONLY after the animation for the movement is done with ENTER_FRAME , only then to start the check if the movement is ok, so I can do the reverse animation.