ComputerCraft Turtle Program: Ultra Stairs v.2

--[[ComputerCraft Turtle Program: Ultra Stairs v.2
    pastebin get WTXCeWQM

.....................EDIT LOG.......................
EDITED: 14, Nov. 2014. Reason: Added a return to start position function called back().
EDITED: 31, March 2015. Reason: Fixed so gravel/sand doesn't break the turtle's groove. Also changed name to match
the other secondary program.
EDITED: 31, March 2015. cont. Also added the cleanup program functionality to this code.
digs out and places stairs
EDITED: 18, September 2015. Reason: Added the ability to make stairs up or down. Also, fixed some things in the EDIT LOG.
pastebin for my orginal stairs program: pastebin get t6kdBeq0
EDITED: 21, Jan. 2016. Reason: Added the ability to make stairs in mid air without the stairs placing upside down. See airStairsUp, airStairsDown for the code.
]]

fuelType = {
coal = 80
}

local block = 1
local stairs = 9
local fuelUsed = 0

local tArgs = { ... }
if #tArgs ~= 1 then
    print( "Usage: Stairs <amount>" )
    return
end

local amount = tonumber( tArgs[1] )

function aboutFace()
    turtle.turnRight()
    turtle.turnRight()
end

function placeStair()--place Stair
    turtle.select(stairs)
    aboutFace()
    turtle.place()
    aboutFace()
end

function digOut()--moves to position next stair
    turtle.select(block)
    turtle.digDown()
    while not
    turtle.forward() do
    turtle.dig()
    end
    turtle.digDown()
    turtle.dig()
    turtle.down()
    fuelUsed = fuelUsed + 1
    print(fuelUsed)
    placeStair()
    turtle.dig()
end
---------------------------------STAIRS DOWN START---------------------------------------
function stairsDown()
--print("distance Down?")
--amount = io.read()
for i = 1, amount do
    digOut()
end

turtle.forward()

function back()
    turtle.up()
    fuelUsed = fuelUsed + 1
    print(fuelUsed)
    turtle.digUp()
    turtle.back()
    fuelUsed = fuelUsed + 1
    print(fuelUsed)
end

for z = 1, amount + 1 do
    back()
end
end
---------------------------------STAIRS DOWN END---------------------------------------
---------------------------------STAIRS UP START---------------------------------------
function digOutUp()
    turtle.digUp()
    turtle.dig()
    turtle.forward()
    fuelUsed = fuelUsed + 1
    print(fuelUsed)
    turtle.dig()
    turtle.digUp()
    turtle.digDown()
    turtle.select(stairs)
    turtle.placeDown()
    turtle.up()
    fuelUsed = fuelUsed + 1
    print(fuelUsed)
end

function back()
    turtle.digUp()
    turtle.down()
    fuelUsed = fuelUsed + 1
    print(fuelUsed)
    turtle.back()
end

function stairsUp()
    for i = 1, amount do
        digOutUp()
    end
    turtle.back()
    fuelUsed = fuelUsed + 1
    print(fuelUsed)
    turtle.down()
    fuelUsed = fuelUsed + 1
    print(fuelUsed)
    turtle.back()
    fuelUsed = fuelUsed + 1
    print(fuelUsed)
    for i = 1, amount - 1 do
        back()
    end
end
---------------------------------STAIRS UP END---------------------------------------
function airBackUp()
    turtle.back()
    fuelUsed = fuelUsed + 1
    print(fuelUsed)
    turtle.down()
    fuelUsed = fuelUsed + 1
    print(fuelUsed)
end
---------------------------------AIR STAIRS UP START---------------------------------------
local t = turtle

function airStairsUp()
    for i = 1, amount do
        t.select(block)
        t.place()
        t.turnLeft()
        t.place()
        t.turnRight()
        t.turnRight()
        t.place()
        t.up()
        fuelUsed = fuelUsed + 1
        print(fuelUsed)
        t.place()
        t.turnLeft()
        t.turnLeft()
        t.place()
        t.turnRight()
        t.select(stairs)
        t.placeDown()
        t.forward()
        fuelUsed = fuelUsed + 1
        print(fuelUsed)
    end
    for i = 1, amount do
    airBackUp()
    end
end

---------------------------------AIR STAIRS UP END---------------------------------------
function airBackDown()
    turtle.up()
    fuelUsed = fuelUsed + 1
    print(fuelUsed)
    turtle.forward()
    fuelUsed = fuelUsed + 1
    print(fuelUsed)
end
---------------------------------AIR STAIRS DOWN START---------------------------------------

function airStairsDown()
    aboutFace()
    for i = 1, amount do
        t.turnLeft() -- turn left
        t.select(block)
        t.place() -- place left
        aboutFace() -- turn right
        t.place() -- place right
        t.turnLeft()-- back to start position
        t.back()
        fuelUsed = fuelUsed + 1
        print(fuelUsed)
        t.select(stairs)
        t.place()
        t.turnLeft() -- turn left
        t.select(block)
        t.place() -- place left
        aboutFace() -- turn right
        t.place() -- place right
        t.turnLeft()-- back to start position
        t.down()
        fuelUsed = fuelUsed + 1
        print(fuelUsed)
        t.placeDown()
    end
    for z = 1, amount + 1 do
    airBackDown()
end
end
---------------------------------AIR STAIRS DOWN END---------------------------------------

function refuel()
local fuelLvl = turtle.getFuelLevel()
local fuelDistance = amount * 2
local fuelNeeded = (fuelDistance - fuelLvl) / fuelType.coal
    print("Fuel level is " ..fuelLvl)
    if fuelNeeded > 0 then
        for i=1,16 do
            turtle.select(i)
            turtle.refuel(math.ceil(fuelNeeded))
        end
    else print("No fuel needed.")
    end
end

function clearTerm()
    term.clear()
    term.setCursorPos(1,1)
end

print("Up or Down?")
    direction = io.read()

function mainProg()
    if direction == "up" then
        print("Dig yes or no?")
        dig = io.read()
        if dig == "yes" then
            clearTerm()
            repeat
                print("Be sure to place the turtle at head level." )
                print("")
                print("Place stairs in slot " .. stairs)
                print("")
                print("Press any key to continue.")
            until os.pullEvent("char")
            clearTerm()
            stairsUp()
        elseif dig == "no" then
            clearTerm()
            repeat
                print("Place the turtle on ground level.")
                print("")
                print("Place blocks in slot " .. block)
                print("")
                print("Place stairs in slot " .. stairs)
                print("")
                print("Press any key to continue.")
            until os.pullEvent("char")
            clearTerm()
            airStairsUp()
        end
    elseif direction == "down" then
        print("Dig yes or no?")
        dig = io.read()
        if dig == "yes" then
            clearTerm()
            repeat
                print("Be sure to place the turtle at ground level." )
                print("")
                print("Place stairs in slot " .. stairs)
                print("")
                print("Press any key to continue.")
            until os.pullEvent("char")
            clearTerm()
            stairsDown()
        elseif dig == "no" then
            clearTerm()
            repeat
                print("Place the turtle on ground level.")
                print("")
                print("Place blocks in slot " .. block)
                print("")
                print("Place stairs in slot " .. stairs)
                print("")
                print("Press any key to continue.")
            until os.pullEvent("char")
            clearTerm()
            airStairsDown()
        end
    end
end
refuel()
mainProg()