new NotCondition(new SentenceHasErrorCondition()),
sellerBehaviour.getTransactionCondition());
engine.add(ConversationStates.ATTENDING, "buy", condition, false,
ConversationStates.ATTENDING, null,
new BehaviourAction(sellerBehaviour, "buy", "sell") {
@Override
public void fireRequestOK(final ItemParserResult res, final Player player, final Sentence sentence, final EventRaiser raiser) {
String chosenItemName = res.getChosenItemName();
// find out if the NPC sells this item, and if so,