Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
If this Defense Position card is changed to Attack Position: Target 1 monster your opponent controls; return that target to the hand.
--マーダーサーカス
--Crass Clown
local s,id=GetID()
function s.initial_effect(c)
	--to hand
	local e1=Effect.CreateEffect(c)
	e1:SetDescription(aux.Stringid(id,0))
	e1:SetProperty(EFFECT_FLAG_CARD_TARGET)
	e1:SetCategory(CATEGORY_TOHAND)
	e1:SetType(EFFECT_TYPE_SINGLE+EFFECT_TYPE_TRIGGER_F)
	e1:SetCode(EVENT_CHANGE_POS)
	e1:SetCondition(s.condition)
	e1:SetTarget(s.target)
	e1:SetOperation(s.operation)
	c:RegisterEffect(e1)
end
function s.condition(e,tp,eg,ep,ev,re,r,rp)
	local c=e:GetHandler()
	return (c:GetPreviousPosition()&POS_DEFENSE)~=0 and c:IsFaceup() and c:IsAttackPos()
end
function s.target(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:IsAbleToHand() end
	if chk==0 then return true end
	Duel.Hint(HINT_SELECTMSG,tp,HINTMSG_RTOHAND)
	local g=Duel.SelectTarget(tp,Card.IsAbleToHand,tp,0,LOCATION_MZONE,1,1,nil)
	Duel.SetOperationInfo(0,CATEGORY_TOHAND,g,#g,0,0)
end
function s.operation(e,tp,eg,ep,ev,re,r,rp)
	local tc=Duel.GetFirstTarget()
	if tc and tc:IsRelateToEffect(e) then
		Duel.SendtoHand(tc,nil,REASON_EFFECT)
	end
end