Accessing Backpack from Server?

I'm trying to access a value inside the Players Backpack via a script from the server:

function onClick(plr)
	local find = game.Players.LocalPlayer.Backpack.Player_Inv:FindFirstChild("Lock Pick")
	if find ~= nil then
		if find.Amount.Value > 0 then
			script.Parent:Destroy()
			find.Amount.Value = find.Amount.Value - 1
		end
	end
end

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

Scripts like these have worked in the past, so I'm not sure what the problem is here. Also, there is nothing printed in the output related to this script. Help?