Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
When this card is Normal Summoned: You can Special Summon 1 Level 4 or lower monster from your hand, also, after that, change this card to Defense Position.
--ゴブリンドバーグ
--Goblindbergh
local s,id=GetID()
function s.initial_effect(c)
	--Special Summon 1 Level 4 or lower monster from your hand
	local e1=Effect.CreateEffect(c)
	e1:SetDescription(aux.Stringid(id,0))
	e1:SetCategory(CATEGORY_SPECIAL_SUMMON+CATEGORY_POSITION)
	e1:SetType(EFFECT_TYPE_SINGLE+EFFECT_TYPE_TRIGGER_O)
	e1:SetCode(EVENT_SUMMON_SUCCESS)
	e1:SetTarget(s.sptg)
	e1:SetOperation(s.spop)
	c:RegisterEffect(e1)
end
function s.spfilter(c,e,tp)
	return c:IsLevelBelow(4) and c:IsCanBeSpecialSummoned(e,0,tp,false,false)
end
function s.sptg(e,tp,eg,ep,ev,re,r,rp,chk)
	if chk==0 then return Duel.GetLocationCount(tp,LOCATION_MZONE)>0
		and Duel.IsExistingMatchingCard(s.spfilter,tp,LOCATION_HAND,0,1,nil,e,tp) end
	Duel.SetOperationInfo(0,CATEGORY_SPECIAL_SUMMON,nil,1,tp,LOCATION_HAND)
	local c=e:GetHandler()
	if c:IsAttackPos() then
		Duel.SetOperationInfo(0,CATEGORY_POSITION,c,1,tp,0)
	end
	Duel.SetPossibleOperationInfo(0,CATEGORY_POSITION,c,1,tp,0)
end
function s.spop(e,tp,eg,ep,ev,re,r,rp)
	if Duel.GetLocationCount(tp,LOCATION_MZONE)==0 then return end
	local c=e:GetHandler()
	Duel.Hint(HINT_SELECTMSG,tp,HINTMSG_SPSUMMON)
	local g=Duel.SelectMatchingCard(tp,s.spfilter,tp,LOCATION_HAND,0,1,1,nil,e,tp)
	if #g>0 and Duel.SpecialSummon(g,0,tp,tp,false,false,POS_FACEUP)>0 and c:IsRelateToEffect(e) and c:IsAttackPos() then
		Duel.BreakEffect()
		Duel.ChangePosition(c,POS_FACEUP_DEFENSE)
	end
end