Lua Random Reward Chest

[Niloahs]

Hello Guys, i hope someone can help me with this script, basicaly what i need is the first equipment the player get in the chest is random, and when he do the quest again, he will get different equipment until completing the set, so the loop start again. Example: player got helmet, second run he got a legs, third run he got a boots...

-- Time Chest by Limos
local config = {
   exhausttime = 1, -- time in seconds
   exhauststorage = 2301,
   level = 50 -- minimum level to open the chest
}

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

     local rewarditems = {
         {id = 26425, chance = 50, count = 1}, -- helmet
         {id = 26426, chance = 60, count = 1}, -- armor
         {id = 26427, chance = 85, count = 1}, -- legs
         {id = 26428, chance = 85, count = 1}, -- boots
     }

     if getPlayerLevel(cid) < config.level then
         doSendMagicEffect(getThingPos(cid), CONST_ME_POFF)
         doPlayerSendCancel(cid, "You need to be level "..config.level.." to open the chest.")
         return true
     end

     if exhaustion.check(cid, config.exhauststorage) then
         local time = exhaustion.get(cid, config.exhauststorage)
         local hours, minutes, seconds = math.floor (time / 3600), math.floor ((time - ((math.floor (time / 3600)) * 3600))/ 60), time - ((math.floor (time/60)) * 60)
         if time >= 3600 then
             text = hours.." "..(hours > 1 and "hours" or "hour")..", "..minutes.." "..(minutes > 1 and "minutes" or "minute").." and "..seconds.." "..(seconds > 1 and "seconds" or "second")
         elseif time >= 120 then
             text = minutes.." "..(minutes > 1 and "minutes" or "minute").." and "..seconds.." "..(seconds > 1 and "seconds" or "second")
         else
             text = seconds.." "..(seconds > 1 and "seconds" or "second")
         end
         doSendMagicEffect(getThingPos(cid), CONST_ME_POFF)
         doPlayerSendTextMessage(cid, MESSAGE_EVENT_ADVANCE, "It is empty. You need to wait "..text.." before you can get a reward again.")
         return true
     end

    local chance = math.random(1,100)
    for i = 1, #rewarditems, 1 do
         if chance < rewarditems[i].chance then
             local info = getItemDescriptions(rewarditems[i].id)
             if rewarditems[i].count > 1 then
                 text = rewarditems[i].count .. " " .. info.plural
             else
                 text = info.article .. " " .. info.name
             end

             local item = doCreateItemEx(rewarditems[i].id, rewarditems[i].count)
             if doPlayerAddItemEx(cid, item, false) ~= RETURNVALUE_NOERROR then
                 doSendMagicEffect(getThingPos(cid), CONST_ME_POFF)
                 text = "You have found a reward. It is to heavy or you have not enough space."
             else
                 text = "You have found " .. text .. "."
                 exhaustion.set(cid, config.exhauststorage, config.exhausttime)
             end
             doPlayerSendTextMessage(cid, MESSAGE_INFO_DESCR, text)
             return true
         else
             chance = chance - rewarditems[i].chance
         end
     end
end