Lol sorry I'm not english native
Answering "John Anderton" ... what the script does is send the choice encrypted.. then after the other guy sends his choice.. the script sends the password to decrypt the original choice.. so the second player can only see first player's choice after he sent his own choice. Thus you can't cheat because you can't see the other person's choice before you send your own.. and by the time you send your own both of you know who won.. so if you change anything the other guy will be able to tell you cheated.
Have fun
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