[FMX04]Need help on Matching Game

Hi im fairly new to Flash and i need help identifying the condition which makes the cards go Disappear. The game was originally made by the creator as a card matching pairs game. So i want to change it instead of 2 cards the game would need to identify 3 identical cards in order to be counted as 1 pair.

So far i have manage to select 3 cards but if those 3 cards are identical only 2 would disappear.

Any help would be great and sorry for my bad english. FLA has been attached.