Why is the sound in this script not working?

The sound in this script dosen't seem to work.

local Lightning = script.Parent.PointLight
while true do
	script.NumberValue.Value = math.random(1, 2)
	if script.NumberValue.Value == 1 then
		script.Parent.Thunder.SoundId = "http://www.roblox.com/loud-thunder-item?id=130818249"--50
		else script.Parent.Thunder.SoundId = "http://www.roblox.com/Thunder-1-item?id=131300620"--21
		end
	wait(7)
	Lightning.Range = 60
	wait(0.7)
	Lightning.Range = 50
	wait(0.1)
	Lightning.Range = 40
	script.Parent.Thunder:Play()
	wait(0.1)
	Lightning.Range = 30
	wait(0.1)
	Lightning.Range = 20
	wait(0.1)
	Lightning.Range = 10
	wait(0.1)
	Lightning.Range = 0
	wait(0.1)
	wait(math.random(1,5))
	end