Lua Bug in actions

[Bug]

Im gettin this error each i perfom the action

function round(num, idp)
    return tonumber(string.format("%." .. (idp or 0) .. "f", num))
end


function onUse(cid, item, fromPosition, itemEx, toPosition)

    local pot = potions[item.actionid]
    if (pot) then
        local itemC = doCreateItemEx(pot.container)
        for i = 1, pot.quantity do
            doAddContainerItem(itemC, pot.item, 100)
        end
       
        local neededCap = 0
        neededCap = ItemType(pot.container):getWeight()
        neededCap = neededCap + (ItemType(pot.item):getWeight() * (pot.quantity * 100))
        neededCap = round(neededCap)
       
        local neededMoney = (pot.quantity * pot.price) * 100
        local pos = getThingPos(cid)
        local player = Player(cid)
        if (player:getMoney() < neededMoney) then
            doPlayerSendTextMessage(cid, 19, "[ItemShop] You don't have enough money, you need "..neededMoney/1000 .." K.")
            doSendMagicEffect(pos, 2)
            return true
        end

        doSendMagicEffect(fromPosition, pot.effect)
       

        it = doPlayerAddItemEx(cid, itemC)

        local word = string.split(ItemType(pot.container):getName(), " ")
        local str = "[ItemShop] You purchased a full "..word[2].." of "..ItemType(pot.item):getName().." for "..neededMoney/1000 .." K."

        if (it ~= 1) then
            doPlayerSendTextMessage(cid, 27, "You don't have enough room or cap on your inventory.")
            return true
        else
            local pos = getThingPos(cid)
            doSendDistanceShoot(fromPosition, pos, pot.distanceEffect)
            doSendMagicEffect(pos, pot.effect)
            doPlayerRemoveMoney(cid, neededMoney)
        end
        doPlayerSendTextMessage(cid, 27, str)   

    end
    return true
end

error:

Lua Script Error: [Action Interface]
data/actions/scripts/other/runesShop.lua:onUse
data/actions/scripts/other/runesShop.lua:20: attempt to perform arithmetic on field 'price' (a nil value)
stack traceback:
        [C]: in function '__mul'
        data/actions/scripts/other/runesShop.lua:20: in function <data/actions/scripts/other/runesShop.lua:6>

 

[Snavy]

What if i told you 'price' is not defined ?

(a nil value = empty, nothing, zero)
you're indexing a nil field of the damn table