Error autofloor:7: attempt to call nil

--[AutoFloorv1]--


print "Starting"

function detectwall() --Removed 'do' here
  if not turtle.detect()  then --Used 'not' instead of '== false' since they are pretty much the same
  turtle.forward()
   else 
      turtle.turnLeft()
      turtle.forward()
      turtle.turnLeft()
    end    
  end
 --[[
Removed an 'end' here since you just need 2
One for the function and one for the 'if'
]]--

function placeblock()
  if not turtle.detectDown()  then
  turtle.placeDown()
    else
      turtle.forward()
    end
  end


while true do
  placeblock()
    detectwall()
    end