Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
When this face-up Attack Position card is targeted for an attack: You can change this card to face-up Defense Position, and if you do, negate that attack.
--EMアメンボート
--Performapal Skeeter Skimmer
local s,id=GetID()
function s.initial_effect(c)
	--negate attack
	local e1=Effect.CreateEffect(c)
	e1:SetDescription(aux.Stringid(id,0))
	e1:SetCategory(CATEGORY_POSITION)
	e1:SetType(EFFECT_TYPE_SINGLE+EFFECT_TYPE_TRIGGER_O)
	e1:SetCode(EVENT_BE_BATTLE_TARGET)
	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 e:GetHandler():IsAttackPos()
end
function s.target(e,tp,eg,ep,ev,re,r,rp,chk)
	if chk==0 then return true end
	Duel.SetOperationInfo(0,CATEGORY_POSITION,e:GetHandler(),1,0,0)
end
function s.operation(e,tp,eg,ep,ev,re,r,rp)
	local c=e:GetHandler()
	if c:IsRelateToEffect(e) and Duel.ChangePosition(c,POS_FACEUP_DEFENSE)~=0 then
		Duel.NegateAttack()
	end
end