How do I fix this script?

I want to create a tool that is when is clicked it deletes itself and replicates another tool in the user's backpack. No matter what I do it does not work. What am I doing wrong?

Here is my script here: ( local script)

local tool = script.parent;

x = game.Players.LocalPlayer.Backpack
z = game.Lighting:WaitForChild("Cookie"):clone()

function onActivated()
	z.Parent = x
	tool: Destroy ()  
end

tool.Activated:connect(onActivated)

Well, from my experience, you do not have to use:

local tool = script.Parent;

If it is in a local script

I also think that the ; in this is not suppose to be there

local tool = script.Parent

if it doesn't work I don't know then.

Try a wait() between z.Parent = x and tool:Destroy() Are you sure z is in lighting? You can try like

repeat
	     wait (.1)
until game.Lighting:FindFirstChild("Cookie")

Are you sure that z is not nil?