Why does my brick change the stage number?

NOTE: I am a beginner in scripting.

I am making a Cave Obby type game. link here: http://www.roblox.com/Cave-Checkpoint-Adventure-place?id=186626805

And, I have a script where it acts like a Spawn Location. When you step on that brick, your stage number changes from 0 to 1. But It doesn't. Why so?

Script:

local sp = script.Parent
local player = game.Players.LocalPlayer

local humanoid = player:FindFirstChild("Humanoid")

function onTouch(sp)
	if (humanoid ~= nil) then 
		if player:onTouch(sp) then
		player.StarterGui.Stage.TextButton.Text="Stage    /    1"
	end
	end
end

script.Parent.Touched:connect(onTouch)

Thanks :)

local sp = script.Parent
local plr = game.Players.LocalPlayer
local B1 = --explain what "B1" is

sp = B1
local stage = plr.StarterGui.Stage

B1.Touched:connect(function()
	stage =  "Stage / 1"
end