What are the numbers of the alphabet in lua?

So I'm trying to create my first script, and I know this is pretty vague but I'm trying to make my script set my walkspeed in a game called ROBLOX and here's what I've got so far.

    ws = game.Players.LocalPlayer.Character.Humanoid.WalkSpeed
    while true do
        if keyPress(27)==true then
            ws = 100
            wait(5)
            ws = 16
        end
    end

Can somebody post the numbers for the alphabet? I couldn't find this anywhere on the internet. ex: Escape = 27