How To Change Brightness Of A PointLight?

My script it to change the brightness and range of a pointlight. Here's the script.

--[[Flickering Fire Script
	By AceOfGreat
--]]

--Variables--
	FL = game.Workspace.Forest.FirePit.FireLight

while true do
	FL.Brightness = 1
	FL.Range = 37.5
	wait(1)
	FL.Brightness = 0.75
	FL.Range = 28.125
	wait(1)
	FL.Brightness = 1.125
	FL.Range = 42.1875
	wait(0.5)
	FL.Brightness = 0.9
	FL.Range = 33.75
	wait(1)
	FL.Brightness = 1.05
	FL.Range = 38
end

I get an error at the first FL.Brightness = 1

Please tell me how to make the script work. Thanks.

What does your output say? (Only answering because commenting is disabled for me.)