how to fix leaderstats not resetting?

im trying to make a gui where you can sell something here is the code for that

local player = game.Players.LocalPlayer
script.Parent.Parent.TextButton.MouseButton1Click:Connect(function()
	local leaderstats = player:WaitForChild("leaderstats")
	local Currency = player.leaderstats.Cash
	local Melon = player.leaderstats.Watermelons
	if Melon.Value > 0 then
		Currency.Value = Currency.Value + Melon.Value *5
		Melon.Value = 0
	end
end)

there is also a part that will add to the thing that you can sell Watermelons in this case

local buttonPressed = false

script.Parent.Touched:Connect(function(hit)
	if not buttonPressed then
		buttonPressed = true
		local player = game.Players:GetPlayerFromCharacter(hit.Parent)
		script.Parent.Transparency = 1
		script.Parent.CanCollide = false
		player.leaderstats.Watermelons.Value = player.leaderstats.Watermelons.Value + 1
		wait(1)
		script.Parent.Transparency = 0
		script.Parent.CanCollide = true
		buttonPressed = false
	end
end)

but after you sell them if you touch the brick again it adds the to value you had before selling how would i fix this to make the melon count start over a zero