Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
If this card is Summoned: Target 1 face-up monster on the field; it loses 800 ATK.
--ダークジェロイド
--Dark Jeroid
local s,id=GetID()
function s.initial_effect(c)
	--Activate
	local e1=Effect.CreateEffect(c)
	e1:SetDescription(aux.Stringid(id,0))
	e1:SetType(EFFECT_TYPE_SINGLE+EFFECT_TYPE_TRIGGER_F)
	e1:SetCode(EVENT_SUMMON_SUCCESS)
	e1:SetProperty(EFFECT_FLAG_CARD_TARGET)
	e1:SetTarget(s.target)
	e1:SetOperation(s.operation)
	c:RegisterEffect(e1)
	local e2=e1:Clone()
	e2:SetCode(EVENT_SPSUMMON_SUCCESS)
	c:RegisterEffect(e2)
	local e3=e1:Clone()
	e3:SetCode(EVENT_FLIP_SUMMON_SUCCESS)
	c:RegisterEffect(e3)
end
function s.target(e,tp,eg,ep,ev,re,r,rp,chk,chkc)
	if chkc then return chkc:IsLocation(LOCATION_MZONE) and chkc:IsFaceup() end
	if chk==0 then return Duel.IsExistingTarget(Card.IsFaceup,tp,LOCATION_MZONE,LOCATION_MZONE,1,nil) end
	Duel.Hint(HINT_SELECTMSG,tp,HINTMSG_FACEUP)
	Duel.SelectTarget(tp,Card.IsFaceup,tp,LOCATION_MZONE,LOCATION_MZONE,1,1,nil)
end
function s.operation(e,tp,eg,ep,ev,re,r,rp)
	local c=e:GetHandler()
	local tc=Duel.GetFirstTarget()
	if tc:IsFaceup() and tc:IsRelateToEffect(e) then
		local e1=Effect.CreateEffect(c)
		e1:SetType(EFFECT_TYPE_SINGLE)
		e1:SetProperty(EFFECT_FLAG_CANNOT_DISABLE)
		e1:SetCode(EFFECT_UPDATE_ATTACK)
		e1:SetValue(-800)
		e1:SetReset(RESET_EVENT|RESETS_STANDARD)
		tc:RegisterEffect(e1)
	end
end