Lua doubts about a npc script

[chauffaille]

Hi, I have a doubt on a npc script

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

local Topic = {}

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

function creatureSayCallback(cid, type, msg)
	if (msgcontains(msg, "hello") or msgcontains(msg, "hi")) and (not npcHandler:isFocused(cid)) then
		npcHandler:say(getPlayerSex(cid) == 0 and "Oi, eu vendo itens especiais." or "como vai? eu vendo itens especiais.", cid)
		Topic[cid] = 0
		npcHandler:addFocus(cid)
	elseif msgcontains(msg, "imperator armor") and npcHandler:isFocused(cid) then
		npcHandler:say("quer comprar imperator armor por 50 pedras do inferno?", cid)
		Topic[cid] = 1
	elseif Topic[cid] == 1 then
		if msgcontains(msg, "yes") then
			if doPlayerRemoveItem(cid, 9020, 50) then
				npcHandler:say("Aqui Está.", cid)
				doPlayerAddItem(cid, 8891, 1)
				doSendMagicEffect(getThingPos(cid), CONST_ME_MAGIC_BLUE)
				Topic[cid] = 0

			else
				npcHandler:say("Voce nao tem pedras do inferno o suficiente.", cid)
				Topic[cid] = 0
			end
		elseif msgcontains(msg, "no") then
			npcHandler:say("Tudo bem.", cid)
			Topic[cid] = 0
		end
	elseif(not npcHandler:isFocused(cid)) then
		return false
	elseif msgcontains(msg, "bye") or msgcontains(msg, "farewell") and npcHander:isFocused(cid) then
		npcHandler:say("Good bye.", cid, TRUE)
		Topic[cid] = nil
		npcHandler:releaseFocus(cid)
	elseif msgcontains(msg, "job") then
		npcHandler:say("I can give you a new {cape} in exchange for a dirty one.", cid)
		Topic[cid] = 0
	end
	return true
end

npcHandler:setCallback(CALLBACK_MESSAGE_DEFAULT, creatureSayCallback)
npcHandler:setMessage(MESSAGE_WALKAWAY, "Good bye.")

how do I later add another item to sell that same script?