Floor maker

-- -----------------------------
-- Floor maker
-- pastebin get gt9FVdK8 floor
-- -----------------------------

even = true
current_slot = 2
x_coord = 0
y_coord = 0

write("Please enter floor lenth ")
lenth = read()
write("Please enter floor width ")
width = read()
write('Clear up block?')
clear_up = read()
if clear_up == 'y' or clear_up == '1' or clear_up == 'true' or clear_up == 'yes' then
  clear_up = true
else
  clear_up = false
end

function checkFuel()
  while turtle.getFuelLevel() < 5 do
    turtle.select(1)
    turtle.refuel(1)
    if turtle.getFuelLevel() < 5 then
      sleep(5)
    end
  end
  turtle.select(16)
end

function placeBlock()
  turtle.select(currentSlot())
  if not turtle.compareDown() then
    turtle.select(16)
    turtle.digDown()
    cleanSlot()
    turtle.select(currentSlot())
    turtle.placeDown()
  end
  turtle.select(16)
end

function cleanSlot()
  if(turtle.getItemCount(16) > 0) then turtle.dropUp() end
end

function currentSlot()
  if turtle.getItemCount(current_slot) < 2 then
    found_slot = false
    while not found_slot do
      for i=2,15 do
        if turtle.getItemCount(i) > 1 then
          found_slot = i
          break
        end
      end
      if not found_slot then
        print("Out of building materials. Please refill and press enter to continue.")
        io.read()
      else
        current_slot = found_slot
      end
    end
  end
  return current_slot
end

turtle.select(16)
placeBlock()
while y_coord < tonumber(width) do
  while x_coord < (tonumber(lenth) - 1) do
    x_coord = x_coord + 1
    checkFuel()
    while not turtle.forward() do
      turtle.dig()
      cleanSlot()
    end
    if clear_up and turtle.detectUp() then
      turtle.digUp()
      cleanSlot()
    end
    placeBlock()
  end
  x_coord = 0
  y_coord = y_coord + 1
  if even then
    turtle.turnRight()
    while not turtle.forward() do
      turtle.dig()
      cleanSlot()
    end
    turtle.turnRight()
  else
    turtle.turnLeft()
    while not turtle.forward() do
      turtle.dig()
      cleanSlot()
    end
    turtle.turnLeft()
  end
  if (y_coord < tonumber(width)) then placeBlock() end
  even = not even
end