Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
Target 1 face-up monster your opponent controls; change that target to face-down Defense Position, then you can return all Field Spell Cards on the field to the hand.
--森のざわめき
--Murmur of the Forest
local s,id=GetID()
function s.initial_effect(c)
	--Activate
	local e1=Effect.CreateEffect(c)
	e1:SetCategory(CATEGORY_POSITION+CATEGORY_TOHAND)
	e1:SetType(EFFECT_TYPE_ACTIVATE)
	e1:SetProperty(EFFECT_FLAG_CARD_TARGET)
	e1:SetCode(EVENT_FREE_CHAIN)
	e1:SetTarget(s.target)
	e1:SetOperation(s.activate)
	c:RegisterEffect(e1)
end
function s.filter(c)
	return c:IsFaceup() and c:IsCanTurnSet()
end
function s.target(e,tp,eg,ep,ev,re,r,rp,chk,chkc)
	if chkc then return chkc:IsControler(1-tp) and chkc:IsLocation(LOCATION_MZONE) and s.filter(chkc) end
	if chk==0 then return Duel.IsExistingTarget(s.filter,tp,0,LOCATION_MZONE,1,nil) end
	Duel.Hint(HINT_SELECTMSG,tp,HINTMSG_FACEUP)
	local g=Duel.SelectTarget(tp,s.filter,tp,0,LOCATION_MZONE,1,1,nil)
	Duel.SetOperationInfo(0,CATEGORY_POSITION,g,1,0,0)
end
function s.rfilter(c)
	return c:IsAbleToHand()
end
function s.activate(e,tp,eg,ep,ev,re,r,rp)
	local tc=Duel.GetFirstTarget()
	if tc:IsRelateToEffect(e) and tc:IsControler(1-tp) and tc:IsFaceup() then
		Duel.ChangePosition(tc,POS_FACEDOWN_DEFENSE)
		local rg=Duel.GetMatchingGroup(s.rfilter,tp,LOCATION_FZONE,LOCATION_FZONE,nil)
		if #rg~=0 and Duel.SelectYesNo(tp,aux.Stringid(id,0)) then
			Duel.BreakEffect()
			Duel.SendtoHand(rg,nil,REASON_EFFECT)
		end
	end
end