Why is NPC Chat not updating?

Hello!

I'm making a story game, which features NPC Chat, and a tram. The script below opens a door, and the most important part is that it also.. How do I say it: Makes the message for the NPC? (The location of the script is: game.StarterGuI.Chat.Frame.script)

Script:

local chat = game.Players.LocalPlayer.PlayerGui.Chat.Frame
local text = chat:WaitForChild("TextLabel")
local name = chat.NpcName
local de = false
local conveyor = workspace.ConveyorStop
local vault = workspace.VaultDoor1
local door1 = vault.OpemDoor1
local door2 = vault.OpenDoor2
local tram = workspace.Tram

function message(speech)
    for i = 1, #speech do
            text.Text = string.sub(speech, 1, i)
            wait()
        end
    end

conveyor.Touched:Connect(function()
    if de == false then
        de = true
                conveyor.CFrame = conveyor.CFrame.LookVector * 30
        wait(3)
        chat.Visible = true
        name.Text = "Walter"
        message("Hello there! My name is Walter, let me open the door for you.")
        wait(2)
                for i = 0, 1, .01 do
                    door1.CFrame = door1.CFrame:Lerp(vault.Door2.CFrame, i)
                    wait()
                end
                    message("So your a new employee, huh? Your name is... Alex- Wait, no last name? Unusual.")
                for i = 0, 1, .01 do
                    door2.CFrame = door2.CFrame:Lerp(vault.Door1.CFrame, i)
                    wait()
                end
        wait(5)
        message("So- Holy! You're 5 minutes late! You better get going...")
        wait(3)
        message("Well, it's nice meeting you! Let me start the rail.")
        wait(1)
        message("Bye!")
        wait(3)
        conveyor.CFrame = conveyor.CFrame.LookVector * 30
        tram:MoveTo(Vector3.new(-233.519, 8.008, -816.172))

    end
end)

Any help would be grateful!