local config = {
[ITEM_GOLD_COIN] = {changeTo = ITEM_PLATINUM_COIN},
[ITEM_PLATINUM_COIN] = {changeBack = ITEM_GOLD_COIN, changeTo = ITEM_CRYSTAL_COIN},
[ITEM_CRYSTAL_COIN] = {changeBack = ITEM_PLATINUM_COIN}
}
function onUse(player, item, fromPosition, target, toPosition, isHotkey)...