function onKill(cid, target, lastHit)

local timeWithinKill = 300 --in seconds
local killsLimit = 3 --limit to die
local lastKill, lastKillTime = nil, nil
local storage = 65535 --storage to check if player has killed another player 'killsLimit' times

        if(isPlayer(target) == false) or (isMonster(cid) == true) then
                return true
        end

        query = db.getResult("select lastKill, lastKillTime from players where id = " .. getPlayerGUID(cid) .. ";")
        if(query:getID() ~= -1) then
                lastKill, lastKillTime = query:getDataInt("lastKill"), query:getDataInt("lastKillTime")
                if(lastKill == getPlayerGUID(target)) then
                        if(os.clock() - lastKillTime) < timeWithinKill then
                                if(getPlayerStorageValue(cid, storage) < 0) then
                                        doPlayerSetStorageValue(cid, storage, 0)
                                end
                                doPlayerSetStorageValue(cid, storage, getPlayerStorageValue(cid, storage) + 1)
                                if(getPlayerStorageValue(cid, storage) >= killsLimit) then
                                        doCreatureAddHealth(cid, -getCreatureHealth(cid))
                                end
                        else
                                doPlayerSetStorageValue(cid, storage, 0)
                        end
                end
                db.executeQuery("update players set lastKill = " .. getPlayerGUID(target) .. ", lastKillTime = " .. os.clock() .. " where id = " .. getPlayerGUID(cid) .. ";")
        else
                return LUA_ERROR
        end
        return true
end