Help me out here.

-- Set up arguments for variables
local tArgs = {...}
if #tArgs ~= 1 then
  print("Incorrect usage of Function.")
  print("mine <width>")
  return
end




-- Set up variables
-- local sEvent, param = os.pullEvent("key")
local w = tonumber(tArgs[1]-1)
local f = 0
local d = 0
local l = 0

-- Setup functions
local function unload() -- Selects each slot in inventory and dumps it on the ground or in chest if available at start
	local rf = f
	setFace(2)
	for i=1,d do
		turtle.forward()
	end
	setFace(3)
	for i=1,l do
		turtle.forward()
	end
	for i=2,16 do
		turtle.select(i)
		turtle.dropDown()
	end
	turtle.select(2)
	setFace(1)
	for i=1,l do
		turtle.forward()
	end
	setFace(0)
	for i=1,d do
		turtle.forward()
	end
	setFace(rf)
	return
end

local function collect() -- running count of inventory to see if full
	local bFull = true
	local nTotalItems = 0
	for n=1,16 do
		local nCount = turtle.getItemCount(n)
		if nCount == 0 then
			bFull = false
		end
		nTotalItems = nTotalItems + nCount
	end	
	if bFull then
		print( "No empty slots left." )
		return false
	end
	return true
end

-- Start of dig functions
local function digDown()
	if turtle.digDown() then
		if not collect() then
			unload()
		end
	end
end

local function digUp()
	if turtle.digUp() then
		if not collect() then
			unload()
		end
	end
end

local function digForward()
	while not turtle.forward() do
		if turtle.dig() then
			if not collect() then
				unload()
			end
		end
	end
end
-- End of dig function

local function digStep() -- setup to dig 3 block high, first in the middle and then top and bottom
	digForward()
	digUp()
	digDown()
end

local function torch()
end

local function face(adj) -- Sets a running number for which way the turtle is facing
	if adj == pos then
		if f == 3 then
			f = 0
		else
			f = f + 1
		end
	elseif adj == neg then
		if f == 0 then
			f = 3
		else
			f = f - 1
		end
	end
end

local function faceRight() -- Turn right and set the current facing direction
	turtle.turnRight()
	face(pos)
end

local function faceLeft() -- Turn left and set the current facing direction
	turtle.turnLeft()
	face(neg)
end

local function setFace(dir) -- Has turtle turn right untill the current facing direction matches the desired facing direction
	local df = tonumber(dir)
	while f ~= df do
		faceRight()
	end
end

local function mine() -- function to mine
	digStep() -- starts the mine forward
	d = d + 1 -- running total of how far from start he's run
	faceRight() -- turn right to start mining the width of the mine
	for i=1,w do -- mines the desired width and keeps a running tally of how far from the left most wall turtle is
		digStep()
		l = l + 1
	end
	faceLeft() -- turn in the other direction to mine back to the leftmost wall
	digStep()
	d = d + 1
	faceLeft()
	for i=1,w do -- mines back to the left most wall
		digStep()
		l = l - 1
	end
	faceRight() -- set to start the next mine cycle
end

mine()
unload()