How do I make a frame go away after it's been viewed once?

game.Players.PlayerAdded:connect(function(plr)
        wait(24)
        plr.PlayerGui.ScreenGui.Intro:Destroy()
end)

is what I tried, any ideas?

Admins: I was streaming while this guy asked me the question. I explained it to on twitch, and posted the code for him to have here. Hope you understand!

game.Players.PlayerAdded:connect(function(plr)
        a = game.ServerStorage.Intro:Clone()
	a.Parent = plr.PlayerGui.ScreenGui
	wait(24)
        plr.PlayerGui.ScreenGui.Intro:Destroy()
end)