[X-TIBIA][ACTION] Sacrifice 6 books to create a NPC

function onUse(cid, item, frompos, item2, topos)
    local positions, npcpos, books, countBooks, tableBooks = {}, {x=759,y=827,z=7,stackpos=1}, {10309, 10310, 10311, 10312, 10314, 10215}, 0, {}
    for x = 1,6 do
        table.insert(positions, {x=756+x,y=828,z=7,stackpos=1})
    end
    if item.itemid == 1945 then
        for i,pos in pairs(positions) do
            book = getThingFromPos(pos)
            if book.itemid == books[i] then
                table.insert(tableBooks, {pos, books[i]})
                countBooks = countBooks+1
            end
        end
        if countBooks == 6 then
            for _,value in pairs(tableBooks) do
                book = getThingFromPos(value[1])
                if book.itemid == value[2] then
                    doRemoveItem(book.uid, 1)
                    doTransformItem(item.uid,item.itemid+1)
                    doCreateNpc('Shenron', npcpos)
                end
            end
        else
            doPlayerSendCancel(cid, "You need at least ".. 6-(countBooks).." books as sacrifice to summon Shenron.")
        end
    else
        doPlayerSendTextMessage(cid,22,"It doesn't seems to work.")
    end
return true
end