Why is this not working? .-. Please help! :)

local isOn = true

function on()
 isOn = true
 script.Parent.PointLight.Enabled = true
script.Sound:Play()
script.Parent.Parent.Lights.Light.Pointlight.Enabled = false
script.Parent.Parent.Lights.Light2.Pointlight.Enabled = false
script.Parent.Parent.Lights.Light3.Pointlight.Enabled = false
script.Parent.Parent.Lights.Light4.Pointlight.Enabled = false
script.Parent.Parent.Lights.Light5.Pointlight.Enabled = false
script.Parent.Parent.Lights.Light6.Pointlight.Enabled = false
script.Parent.Parent.Lights.Light7.Pointlight.Enabled = false
script.Parent.Parent.Lights.Light8.Pointlight.Enabled = false
script.Parent.Parent.Lights.Light9.Pointlight.Enabled = false
end

function off()
 isOn = false
 script.Parent.PointLight.Enabled = false
script.Sound:Stop()
script.Parent.Parent.Lights.Light.Pointlight.Enabled = true
script.Parent.Parent.Lights.Light2.Pointlight.Enabled = true
script.Parent.Parent.Lights.Light3.Pointlight.Enabled = true
script.Parent.Parent.Lights.Light4.Pointlight.Enabled = true
script.Parent.Parent.Lights.Light5.Pointlight.Enabled = true
script.Parent.Parent.Lights.Light6.Pointlight.Enabled = true
script.Parent.Parent.Lights.Light7.Pointlight.Enabled = true
script.Parent.Parent.Lights.Light8.Pointlight.Enabled = true
script.Parent.Parent.Lights.Light9.Pointlight.Enabled = true
end

function onClicked()
 
 if isOn == true then off() else on() end

end

script.Parent.ClickDetector.MouseClick:connect(onClicked)

on()

Please help! Here is the output : 21:29:19.030 - Script 'Workspace.TARDIS .Controls.Part.Light', Line 22 - global off 21:29:19.031 - Script 'Workspace.TARDIS.Controls.Part.Light', Line 35 21:29:19.032 - Stack End 21:29:19.033 - Disconnected event because of exception

Please give me a valid explanation of why the hell this doesn't work? :(((