public Packet buycoin(int id)
    {
        int price = item.getBuyCoins(id);
        if (price == -1) {
            return getErrorPacket(noitem,head_buycoins);
        }
        int ccoins = bot.getCoins();
        if (ccoins < price) {
            return getErrorPacket(nocoins,head_buycoins);
        }
        int slot = slotAvaible();
        if(slot == -1) {
            return getErrorPacket(noslot,head_buycoins);
        }
        bot.setCoins(ccoins-price);
        bot.setInvent(id, slot);
        return bot.getInventPacket(head_buycoins);
    }