How do you make a material changer with button?

I am trying to make a light switch that changes the material too, but I can't figure it out. (Btw its not all my script, and I suck at scripting. So please go easy on me D;)

function onClicked(plyr)
	v = script.Parent.Value
	if v.Value == false then
		v.Value = true
		_G.Light.BrickColor = BrickColor.new("Fossil")
		game.workspace.Light.Material = Enum.Neon
		script.Parent.BrickColor = BrickColor.new("Bright red")
		_G.Light.PointLight.Enabled = true
	elseif v.Value == true then
		v.Value = false
		_G.Light.BrickColor = BrickColor.new("Black")
			game.workspace.Light.Material = Enum.SmoothPlastic
		script.Parent.BrickColor = BrickColor.new("Bright green")
		_G.Light.PointLight.Enabled = false
	end
end
script.Parent.ClickDetector.MouseClick:connect(onClicked)

If you can help, then thanks!