Turtle Remove 2.0

--Input
  print("This program will remove all blocks in an area defined by the following parameters.")
  print("")
  print("------------------------------------------------------------------------------")
  print("")

  print("Enter area length.")
  local length = tonumber(io.read())
  length = length or 5
  print("Area length set to: " .. length .. " blocks.")
  print("")

  print("Enter area width.")
  local width = tonumber(io.read())
  width = width or length
  print("Area width set to: " .. width .. " blocks.")
  print("")

  print("Should the turtle move left or right?")
  print("Type 0 or leave blank for Right.")
  print("Type 1 for Left.")
  local hdir = tonumber(io.read())
  hdir = hdir or 0
  if (hdir ~= 1) then
    hdir = 0
    hdirst = "Right"
   else
    hdir = 1
    hdirst = "Left"
  end
  hhdir = hdir
  print("Turtle will move " .. hdirst)
  print("")

  print("Should the turtle move up or down?")
  print("Type 0 or leave blank for down.")
  print("Type 1 for up.")
  local vdir = tonumber(io.read())
  vdir = vdir or 0
  if (vdir ~= 1) then
    vdir = 0
    vdirst = "Down"
   else
    vdir = 1
    vdirst = "Up"
  end
  print("Turtle will move " .. vdirst)
  print("")

  print("How far vertically should the turtle travel?")
  print("Leave blank for 1")
  local height = tonumber(io.read())
  height = height or 1
  if (height < 2) then
    height = 1
  end
  print("Area height set to: " .. height .. " blocks.")
  print("")
  print("---------------------------------------")
  print("")
  print("Removing a " .. length .. "x" .. width .. "x" .. height .. " area to the " .. hdirst .. " of the turtle, digging " .. vdirst .. ".")


--Functions

  function checkfuel()
    if turtle.getFuelLevel() < 10 then
      for i = 1, 16 do
        turtle.select(i)
        turtle.refuel(1)
      end
      turtle.select(1)
    end
  end

  function turnaround()
    turtle.turnRight()
    sleep(0.1)
    turtle.turnRight()
    sleep(0.1)
  end

  function dig()
    while turtle.detect() do
      turtle.dig()
      sleep(0.5)
    end
  end

  function digUp()
    while turtle.detectUp() do
      turtle.digUp()
      sleep(0.5)
    end
  end

  function digDown()
    while turtle.detectDown() do
      turtle.digDown()
      sleep(0.5)
    end
  end

  function nextcolumn()
    for i = (vdir + 1), height do
      checkfuel()
      if vdir == 1 then
        turtle.down()
       else
        turtle.up()
      end
    end
  end

  function backlength()
    turnaround()
    for i = 1, length do
      dig()
      checkfuel()
      turtle.forward()
    end
    turnaround()
  end

  function dircheck()
    if hdir == 0 then
      turtle.turnRight()
      dig()
      checkfuel()
      turtle.forward()
      turtle.turnLeft()
     else
      turtle.turnLeft()
      dig()
      checkfuel()
      turtle.forward()
      turtle.turnRight()
    end
  end


--Main

  for w = 1, width do
    dig()
    checkfuel()
    turtle.forward()

    for l = 1, length do

      for h = (vdir + 1), height do
        if vdir == 1 then
            digUp()
            checkfuel()
            turtle.up()
         else
          digDown()
          checkfuel()
          turtle.down()
        end
      end
      nextcolumn()
      if l < length then
        dig()
        checkfuel()
        turtle.forward()
      end
    end
    backlength()
    if w < width then
      dircheck()
    end
  end