Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
"Watt" monsters you control cannot be destroyed by battle while they are attacking.
--エレキーウィ
--Wattkiwi
local s,id=GetID()
function s.initial_effect(c)
	--indes
	local e1=Effect.CreateEffect(c)
	e1:SetType(EFFECT_TYPE_FIELD)
	e1:SetCode(EFFECT_INDESTRUCTABLE_BATTLE)
	e1:SetRange(LOCATION_MZONE)
	e1:SetTargetRange(LOCATION_MZONE,0)
	e1:SetTarget(s.indtg)
	e1:SetValue(1)
	c:RegisterEffect(e1)
end
s.listed_series={SET_WATT}
function s.indtg(e,c)
	return c:IsSetCard(SET_WATT) and c==Duel.GetAttacker()
end