Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
When your opponent activates a monster effect in their hand: Negate that activation, then if they have any cards in their hand, you discard 1 card from their hand (of their choice).
--ＸＸクルージョン
--XX-clusion
--Scripted by Hatter
local s,id=GetID()
function s.initial_effect(c)
	--Negate activation
	local e1=Effect.CreateEffect(c)
	e1:SetCategory(CATEGORY_NEGATE+CATEGORY_HANDES)
	e1:SetType(EFFECT_TYPE_ACTIVATE)
	e1:SetCode(EVENT_CHAINING)
	e1:SetCondition(s.negcon)
	e1:SetTarget(s.negtg)
	e1:SetOperation(s.negop)
	c:RegisterEffect(e1)
end
function s.negcon(e,tp,eg,ep,ev,re,r,rp)
	return rp==1-tp and re:GetActivateLocation()==LOCATION_HAND
		and re:IsMonsterEffect() and Duel.IsChainNegatable(ev)
end
function s.negtg(e,tp,eg,ep,ev,re,r,rp,chk)
	if chk==0 then return true end
	Duel.SetOperationInfo(0,CATEGORY_NEGATE,eg,1,0,0)
end
function s.negop(e,tp,eg,ep,ev,re,r,rp)
	if Duel.NegateActivation(ev) and Duel.GetFieldGroupCount(1-tp,LOCATION_HAND,0)>0 then
		Duel.BreakEffect()
		Duel.Hint(HINT_SELECTMSG,tp,HINTMSG_DISCARD)
		Duel.DiscardHand(1-tp,nil,1,1,REASON_EFFECT|REASON_DISCARD,nil)
	end
end