Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
Once per turn, when the battle position of this card is changed, you can select 1 monster your opponent controls and change its battle position.
--アースクエイク・ジャイアント
--Earthquake Giant
local s,id=GetID()
function s.initial_effect(c)
	--Change battle position
	local e1=Effect.CreateEffect(c)
	e1:SetDescription(aux.Stringid(id,0))
	e1:SetType(EFFECT_TYPE_SINGLE+EFFECT_TYPE_TRIGGER_O)
	e1:SetProperty(EFFECT_FLAG_CARD_TARGET)
	e1:SetCode(EVENT_CHANGE_POS)
	e1:SetCountLimit(1)
	e1:SetCondition(s.poscon)
	e1:SetTarget(s.postg)
	e1:SetOperation(s.posop)
	c:RegisterEffect(e1)
end
function s.poscon(e,tp,eg,ep,ev,re,r,rp)
	local c=e:GetHandler()
	if c:IsStatus(STATUS_CONTINUOUS_POS) then return false end
	if c:IsPosition(POS_FACEUP_ATTACK) then
		return c:IsPreviousPosition(POS_FACEUP_DEFENSE|POS_FACEDOWN_DEFENSE)
	elseif c:IsPosition(POS_FACEUP_DEFENSE) then
		return c:IsPreviousPosition(POS_FACEUP_ATTACK)
	end
end
function s.postg(e,tp,eg,ep,ev,re,r,rp,chk,chkc)
	if chkc then return chkc:IsLocation(LOCATION_MZONE) and chkc:IsControler(1-tp) and chkc:IsCanChangePosition() end
	if chk==0 then return Duel.IsExistingTarget(Card.IsCanChangePosition,tp,0,LOCATION_MZONE,1,nil) end
	Duel.Hint(HINT_SELECTMSG,tp,HINTMSG_POSCHANGE)
	local g=Duel.SelectTarget(tp,Card.IsCanChangePosition,tp,0,LOCATION_MZONE,1,1,nil)
	Duel.SetOperationInfo(0,CATEGORY_POSITION,g,1,0,0)
end
function s.posop(e,tp,eg,ep,ev,re,r,rp)
	local tc=Duel.GetFirstTarget()
	if tc:IsRelateToEffect(e) then
		Duel.ChangePosition(tc,POS_FACEUP_DEFENSE,POS_FACEDOWN_DEFENSE,POS_FACEUP_ATTACK,POS_FACEUP_ATTACK)
	end
end