Computercraft Basic StairDown Program

print("Building Stairs...")
turtle.forward()
turtle.select(1)
count=1
for inv=1,9 do
  while turtle.getItemCount(inv) > 0 and not (turtle.detectDown()) do
    turtle.placeDown()
    turtle.forward()
    turtle.down()
    count=count+1
  end
end

for i=1,(count-1) do
  turtle.up()
  turtle.back()
end

turtle.back()
print("Finished")
print("Placed ",count," blocks")