Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
If there are monsters with the same name on the field, those monsters gain 500 ATK/DEF.
--アクアの合唱
--Aqua Chorus
local s,id=GetID()
function s.initial_effect(c)
	--Activate
	local e1=Effect.CreateEffect(c)
	e1:SetType(EFFECT_TYPE_ACTIVATE)
	e1:SetProperty(EFFECT_FLAG_DAMAGE_STEP)
	e1:SetCode(EVENT_FREE_CHAIN)
	e1:SetCondition(aux.StatChangeDamageStepCondition)
	c:RegisterEffect(e1)
	--Increase ATK
	local e2=Effect.CreateEffect(c)
	e2:SetType(EFFECT_TYPE_FIELD)
	e2:SetCode(EFFECT_UPDATE_ATTACK)
	e2:SetRange(LOCATION_SZONE)
	e2:SetTargetRange(LOCATION_MZONE,LOCATION_MZONE)
	e2:SetTarget(s.target)
	e2:SetValue(500)
	c:RegisterEffect(e2)
	local e3=e2:Clone()
	e3:SetCode(EFFECT_UPDATE_DEFENSE)
	c:RegisterEffect(e3)
end
function s.target(e,c)
	return Duel.IsExistingMatchingCard(aux.FaceupFilter(Card.IsCode,c:GetCode()),0,LOCATION_MZONE,LOCATION_MZONE,1,c)
end