Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
When your opponent declares a direct attack: You can banish 1 Pyro monster in your GY; negate the attack. Once per turn, during your Standby Phase, pay 500 LP or destroy this card.
--ファイヤー・ウォール
--Firewall
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)
	c:RegisterEffect(e1)
	--Negate a direct attack
	local e2=Effect.CreateEffect(c)
	e2:SetDescription(aux.Stringid(id,0))
	e2:SetType(EFFECT_TYPE_QUICK_O)
	e2:SetRange(LOCATION_SZONE)
	e2:SetCode(EVENT_ATTACK_ANNOUNCE)
	e2:SetCondition(s.atkcon)
	e2:SetCost(s.atkcost)
	e2:SetTarget(s.atktg)
	e2:SetOperation(function() Duel.NegateAttack() end)
	c:RegisterEffect(e2)
	--Maintenance cost
	local e3=Effect.CreateEffect(c)
	e3:SetType(EFFECT_TYPE_FIELD+EFFECT_TYPE_CONTINUOUS)
	e3:SetProperty(EFFECT_FLAG_CANNOT_DISABLE+EFFECT_FLAG_UNCOPYABLE)
	e3:SetCode(EVENT_PHASE|PHASE_STANDBY)
	e3:SetRange(LOCATION_SZONE)
	e3:SetCountLimit(1)
	e3:SetCondition(function(e,tp) return Duel.IsTurnPlayer(tp) end)
	e3:SetOperation(s.mtop)
	c:RegisterEffect(e3)
end
function s.atkcon(e,tp,eg,ep,ev,re,r,rp)
	return Duel.GetAttacker():IsControler(1-tp) and Duel.GetAttackTarget()==nil
end
function s.cfilter(c)
	return c:IsRace(RACE_PYRO) and c:IsAbleToRemoveAsCost() and aux.SpElimFilter(c,true)
end
function s.atkcost(e,tp,eg,ep,ev,re,r,rp,chk)
	if chk==0 then return Duel.IsExistingMatchingCard(s.cfilter,tp,LOCATION_MZONE|LOCATION_GRAVE,0,1,nil) end
	Duel.Hint(HINT_SELECTMSG,tp,HINTMSG_REMOVE)
	local g=Duel.SelectMatchingCard(tp,s.cfilter,tp,LOCATION_MZONE|LOCATION_GRAVE,0,1,1,nil)
	Duel.Remove(g,POS_FACEUP,REASON_COST)
end
function s.atktg(e,tp,eg,ep,ev,re,r,rp,chk)
	if chk==0 then return e:GetHandler():GetFlagEffect(id)==0 end
	e:GetHandler():RegisterFlagEffect(id,RESET_CHAIN,0,1)
end
function s.mtop(e,tp,eg,ep,ev,re,r,rp)
	if Duel.CheckLPCost(tp,500) and Duel.SelectYesNo(tp,aux.Stringid(id,2)) then
		Duel.PayLPCost(tp,500)
	else
		Duel.Destroy(e:GetHandler(),REASON_COST)
	end
end