Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
When a "Heroic" monster you control is targeted for an attack: Target another Level 4 or lower "Heroic" monster you control; double its ATK during this Battle Phase, then change the attack target to it and proceed to damage calculation, but monsters cannot be destroyed by this battle.
--ヒロイック・アドバンス
--Heroic Advance
local s,id=GetID()
function s.initial_effect(c)
	--Activate
	local e1=Effect.CreateEffect(c)
	e1:SetType(EFFECT_TYPE_ACTIVATE)
	e1:SetProperty(EFFECT_FLAG_CARD_TARGET)
	e1:SetCode(EVENT_BE_BATTLE_TARGET)
	e1:SetCondition(s.condition)
	e1:SetTarget(s.target)
	e1:SetOperation(s.activate)
	c:RegisterEffect(e1)
end
s.listed_series={SET_HEROIC}
function s.condition(e,tp,eg,ep,ev,re,r,rp)
	local d=Duel.GetAttackTarget()
	return d:IsFaceup() and d:IsControler(tp) and d:IsSetCard(SET_HEROIC)
end
function s.filter(c)
	return c:IsFaceup() and c:IsLevelBelow(4) and c:IsSetCard(SET_HEROIC)
end
function s.target(e,tp,eg,ep,ev,re,r,rp,chk,chkc)
	if chkc then return chkc:IsLocation(LOCATION_MZONE) and chkc:IsControler(tp) and s.filter(chkc) end
	if chk==0 then return Duel.IsExistingTarget(s.filter,tp,LOCATION_MZONE,0,1,Duel.GetAttackTarget()) end
	Duel.Hint(HINT_SELECTMSG,tp,HINTMSG_TARGET)
	Duel.SelectTarget(tp,s.filter,tp,LOCATION_MZONE,0,1,1,Duel.GetAttackTarget())
	Duel.GetAttacker():CreateEffectRelation(e)
end
function s.activate(e,tp,eg,ep,ev,re,r,rp)
	local a=Duel.GetAttacker()
	local tc=Duel.GetFirstTarget()
	if tc:IsFaceup() and tc:IsRelateToEffect(e) and not tc:IsImmuneToEffect(e) 
		and a:CanAttack() and a:IsRelateToEffect(e) and not a:IsImmuneToEffect(e)then
		local e1=Effect.CreateEffect(e:GetHandler())
		e1:SetType(EFFECT_TYPE_SINGLE)
		e1:SetCode(EFFECT_SET_ATTACK_FINAL)
		e1:SetValue(tc:GetAttack()*2)
		e1:SetReset(RESET_EVENT|RESETS_STANDARD|RESET_PHASE|PHASE_BATTLE)
		tc:RegisterEffect(e1)
		local e2=Effect.CreateEffect(e:GetHandler())
		e2:SetType(EFFECT_TYPE_SINGLE)
		e2:SetCode(EFFECT_INDESTRUCTABLE_BATTLE)
		e2:SetValue(1)
		e2:SetReset(RESET_EVENT|RESETS_STANDARD|RESET_PHASE|PHASE_DAMAGE)
		tc:RegisterEffect(e2)
		local e3=e2:Clone()
		a:RegisterEffect(e3)
		Duel.CalculateDamage(a,tc)
	end
end