Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
If your opponent controls a card in their Field Zone and you do not: Activate 1 Field Spell Card from your Deck. You can only activate 1 "Pop-Up" per turn.
--ポップルアップ
--Pop-Up
local s,id=GetID()
function s.initial_effect(c)
	--Activate
	local e1=Effect.CreateEffect(c)
	e1:SetType(EFFECT_TYPE_ACTIVATE)
	e1:SetCode(EVENT_FREE_CHAIN)
	e1:SetCountLimit(1,id,EFFECT_COUNT_CODE_OATH)
	e1:SetCondition(s.condition)
	e1:SetTarget(s.target)
	e1:SetOperation(s.operation)
	c:RegisterEffect(e1)
end
function s.condition(e,tp,eg,ep,ev,re,r,rp)
	return Duel.GetFieldCard(tp,LOCATION_FZONE,0)==nil and Duel.GetFieldCard(1-tp,LOCATION_FZONE,0)~=nil
end
function s.filter(c,tp)
	return c:IsFieldSpell() and c:GetActivateEffect():IsActivatable(tp,true,true)
end
function s.target(e,tp,eg,ep,ev,re,r,rp,chk)
	if chk==0 then return Duel.IsExistingMatchingCard(s.filter,tp,LOCATION_DECK,0,1,nil,tp) end
	if not Duel.CheckPhaseActivity() then Duel.RegisterFlagEffect(tp,CARD_MAGICAL_MIDBREAKER,RESET_CHAIN,0,1) end
end
function s.operation(e,tp,eg,ep,ev,re,r,rp)
	Duel.Hint(HINT_SELECTMSG,tp,aux.Stringid(id,0))
	local tc=Duel.SelectMatchingCard(tp,s.filter,tp,LOCATION_DECK,0,1,1,nil,tp):GetFirst()
	Duel.ActivateFieldSpell(tc,e,tp,eg,ep,ev,re,r,rp)
end