NPC SELLER ITEMS

[dfsuno]

Good morning Otland community, could you help me with a npc I need to sell the items x items not for money,and add how many loads the item will have when selling it, it only appears with one.

excuse me, my english is terrible.
I add the npc

local keywordHandler = KeywordHandler:new()
    local npcHandler = NpcHandler:new(keywordHandler)
    NpcSystem.parseParameters(npcHandler)

    function onCreatureAppear(cid) npcHandler:onCreatureAppear(cid) end
    function onCreatureDisappear(cid) npcHandler:onCreatureDisappear(cid) end
    function onCreatureSay(cid, type, msg) npcHandler:onCreatureSay(cid, type, msg) end
    function onThink() npcHandler:onThink() end

    local shopWindow = {}
    local keys = {
         {id = 7869, buy = 500, name = "knight sword training ", actionid = 1443},
         {id = 7880, buy = 200, name = "knight club training ", actionid = 1443},
         {id = 7875, buy = 500, name = "knight axe training ", actionid = 1443},
       {id = 7864, buy = 500, name = "Paladin training ", actionid = 1443},
       {id = 7773, buy = 500, name = "Druid training ", actionid = 1443},
       {id = 7754, buy = 500, name = "Sorcerer training ", actionid = 1443},

    }

    local onBuy = function(cid, item, subType, amount, ignoreCap, inBackpacks)
         if doPlayerRemoveMoney(cid, shopWindow[item].Price) then
             local thing = doPlayerAddItem(cid, shopWindow[item].ID, 1)
             doItemSetAttribute(thing, 'aid', shopWindow[item].Actionid)
             doPlayerSendTextMessage(cid, MESSAGE_INFO_DESCR, "You have bought a "..shopWindow[item].KeyName.." for "..shopWindow[item].Price.." gold.")
         else
             selfSay("You don't have enough money.", cid)
         end
         return true
    end


    function creatureSayCallback(cid, type, msg)
         if not npcHandler:isFocused(cid) then
             return false
         end

         if msgcontains(msg, 'trade') then
             for var, item in pairs(keys) do
                 shopWindow[item.id] = {ID = item.id, Price = item.buy, KeyName = item.name, Actionid = item.actionid}
             end
             openShopWindow(cid, keys, onBuy, onSell)
         end
         return true
    end

    npcHandler:setCallback(CALLBACK_MESSAGE_DEFAULT, creatureSayCallback)
    npcHandler:addModule(FocusModule:new())

thanks to all.

I USE tfs 4