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.