Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
During either player's Battle Step, while an attack is occurring: You can banish this card from your Graveyard; negate the attack. You can only use the effect of "Bacon Saver" once per Duel.
--タスケルトン
--Bacon Saver
local s,id=GetID()
function s.initial_effect(c)
	--disable attack
	local e1=Effect.CreateEffect(c)
	e1:SetDescription(aux.Stringid(id,0))
	e1:SetType(EFFECT_TYPE_QUICK_O)
	e1:SetCode(EVENT_FREE_CHAIN)
	e1:SetHintTiming(TIMING_BATTLE_PHASE)
	e1:SetRange(LOCATION_GRAVE)
	e1:SetCountLimit(1,id,EFFECT_COUNT_CODE_DUEL)
	e1:SetCondition(s.condition)
	e1:SetCost(Cost.SelfBanish)
	e1:SetOperation(s.operation)
	c:RegisterEffect(e1)
end
function s.condition(e,tp,eg,ep,ev,re,r,rp)
	return Duel.GetAttacker()~=nil
end
function s.operation(e,tp,eg,ep,ev,re,r,rp)
	Duel.NegateAttack()
end