Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
If you control a Synchro Monster, you can Special Summon this card (from your hand). You can only Special Summon "Junk Dragonlet" once per turn this way. When a Synchro Monster you control declares an attack: You can banish this card from your GY; that monster you control gains 800 ATK until the end of this turn. You can only use this effect of "Junk Dragonlet" once per turn.
--ジャンク・ドラゴンセント
--Junk Dragonlet
--scripted by Naim
local s,id=GetID()
function s.initial_effect(c)
	--Special Summon it from the hand if you control a Synchro monster
	local e1=Effect.CreateEffect(c)
	e1:SetDescription(aux.Stringid(id,0))
	e1:SetType(EFFECT_TYPE_FIELD)
	e1:SetProperty(EFFECT_FLAG_UNCOPYABLE)
	e1:SetCode(EFFECT_SPSUMMON_PROC)
	e1:SetRange(LOCATION_HAND)
	e1:SetCountLimit(1,id,EFFECT_COUNT_CODE_OATH)
	e1:SetCondition(s.spcon)
	c:RegisterEffect(e1)
	--A Synchro monster you control gains 800 ATK when it declares an attack
	local e2=Effect.CreateEffect(c)
	e2:SetDescription(aux.Stringid(id,1))
	e2:SetCategory(CATEGORY_ATKCHANGE)
	e2:SetType(EFFECT_TYPE_FIELD+EFFECT_TYPE_TRIGGER_O)
	e2:SetCode(EVENT_ATTACK_ANNOUNCE)
	e2:SetRange(LOCATION_GRAVE)
	e2:SetCountLimit(1,{id,1})
	e2:SetCondition(s.atkcond)
	e2:SetCost(Cost.SelfBanish)
	e2:SetTarget(function(e,tp,eg,ep,ev,re,r,rp,chk) if chk==0 then return Duel.GetAttacker():IsRelateToBattle() end end)
	e2:SetOperation(s.atkop)
	c:RegisterEffect(e2)
end
function s.spcon(e,c)
	if c==nil then return true end
	local tp=c:GetControler()
	return Duel.GetLocationCount(tp,LOCATION_MZONE)>0
		and Duel.IsExistingMatchingCard(aux.FaceupFilter(Card.IsType,TYPE_SYNCHRO),tp,LOCATION_MZONE,0,1,nil)
end
function s.atkcond(e,tp,eg,ep,ev,re,r,rp)
	local at=Duel.GetAttacker()
	return at:IsControler(tp) and at:IsType(TYPE_SYNCHRO)
end
function s.atkop(e,tp,eg,ep,ev,re,r,rp)
	local at=Duel.GetAttacker()
	if at:IsFaceup() and at:IsControler(tp) and at:IsRelateToBattle() then
		--Gains 800 ATK
		local e1=Effect.CreateEffect(e:GetHandler())
		e1:SetType(EFFECT_TYPE_SINGLE)
		e1:SetCode(EFFECT_UPDATE_ATTACK)
		e1:SetValue(800)
		e1:SetReset(RESETS_STANDARD_PHASE_END)
		at:RegisterEffect(e1)
	end
end