House Builder After Choise Size

-- Code by Plazter --
-- 2013 --
-- House builder --
-- Description: This is a turtle program, to build houses as you wish, right now it can only take a even number
--Heres an example on how to start it to build: Build 4=the widht. 3= the height of the house

local args = {...}
turtle.up()

if args[1] == nil or args[1] == "help" then
	print("<program name> <width> <Height>")
  return
end

local slot = 1

function wall()
  for i = 1,args[1] -1 do
   turtle.placeDown()
	turtle.forward()
  if turtle.getItemCount(slot) < 1 then
   slot = slot+1
	turtle.select(slot)
  end
end
end

function right()
  turtle.turnRight()
end

function left()
  turtle.turnLeft()
end


function square()
	 wall()
	 right()
	 wall()
	 right()
	wall()
	right()
	wall()
	 right()
end

function roof() -- Work in progress
  for i = 1,args[1] /2 do
   wall()
	right()
   turtle.placeDown()
   turtle.forward()
   right()
   wall()
   left()
   turtle.placeDown()
turtle.forward()
  left()
end
   turtle.back()
	for i = 1,args[2] +1 do
	 turtle.down()
  right()
  right()
end
end

function layer()
  for i = 1, args[2] do
	 square()
   turtle.up()
  end
end

-- The program --
layer()
roof()
print("Done building..")