How To Script "Click To Type" SurfaceGUI?

So I want to make a message board in my game where you can click the part and type what you want on there. I want what the players typed on there to stay even after you close the game. Basically it needs to stay until edited again. I've looked up videos on YouTube, but I can't find what I'm looking for. These are the objects inserted so far:

• Part
  • SurfaceGUI
    • Frame
      • TextButton
        • Script
      • TextLabel

The script says:

script.Parent.MouseButton1Click:Connect:function()

end))

May someone please tell me if I've done something wrong and how to fix it and also what I need to add?

###Instead of placing the SurfaceGui in workspace, place in the StarterGui, and set the Adornee to the part. And from a local script:

-- LocalScript

script.Parent.MouseButton1Click:Connect(function()
    -- code 
end)

###Edit: The text will not change until new text is inputted.