Frag Reward help

[Grzegory]

Could you help me set this script that you can get 1 reward only 1 time ? Help eace:

local fragRewards =
{
	--frag rewards configuration
	--from highest to lowest (by frags)
	{frags = 5, itemid = 3960}, --<1citizen>
        {frags = 5, itemid = 3960}
        {frags = 5, itemid = 3960}
        {frags = 5, itemid = 3960}
}

local function getRewardByName(name)
	local tmp = name:lower()
	local tmp2 = ""
	for _, reward in pairs(fragRewards) do
		tmp2 = getItemNameById(reward.itemid)
		if(tmp == tmp2) then
			reward.name = tmp2
			return reward
		end
	end

	return FALSE
end

function onSay(cid, words, param)
	if(param == "" or param:lower() == "list") then
		local str = "#Frag rewards:"
		for _, reward in pairs(fragRewards) do
			str = str .. "\n" .. getItemNameById(reward.itemid) .. " " .. (reward.count ~= nil and "(x" .. reward.count .. ")" or "") .. "- " .. reward.frags .. " frags"
			end

		doPlayerPopupFYI(cid, str .. "\n\nExample: " .. words .. " magic plate armor")
		return TRUE
	end

	local reward = getRewardByName(param)
	if(reward == FALSE) then
		doPlayerSendTextMessage(cid, MESSAGE_INFO_DESCR, "Invalid item specified. Please use '" .. words .. " list' command to get valid rewards list.")
		return TRUE
	end

	local playerFrags = getPlayerFrags(cid)
	if(playerFrags < reward.frags) then
		doPlayerSendTextMessage(cid, MESSAGE_INFO_DESCR, "You need " .. reward.frags .. " frags for this item.")
		return TRUE
	end

	itemWeight = getItemWeightById(reward.itemid, reward.count)
	if(isItemRune(reward.itemid) == TRUE) then
		itemWeight = getItemWeightById(reward.itemid, 1)
	end

	local rewardItem = doCreateItemEx(reward.itemid, reward.count)
	local freeCap = getPlayerFreeCap(cid)
	if(itemWeight > freeCap or doPlayerAddItemEx(cid, rewardItem) ~= RETURNVALUE_NOERROR) then
		doPlayerSendTextMessage(cid, MESSAGE_INFO_DESCR, "You don't have enought space/capacity for this item.")
		return TRUE
	end

	doPlayerSendTextMessage(cid, MESSAGE_INFO_DESCR, "You have bought " .. reward.name .. " for " .. reward.frags .. " frags.")
	doPlayerAddFrags(cid, -reward.frags)
	return TRUE
end