Moving No Breaking

while true do
 local action = math.random(1,8)


 if action == 1 then
  turtle.turnLeft()
 end

 if action == 2 then
  turtle.turnRight()
 end

 if action == 3 then
  local distance = math.random(1,5)
  for i = 1,distance do
   turtle.forward()
   if turtle.detectDown() then
    turtle.select(1)
   else
    turtle.down()
   end
  end
 end

 if action == 4 then
  local distance = math.random(1,5)
  for i = 1,distance do
   turtle.forward()
   if turtle.detectDown() then
    turtle.select(1)
   else
    turtle.down()
   end
  end
 end

 if action == 5 then
  local distance = math.random(1,5)
  for i = 1,distance do
   turtle.forward()
   if turtle.detectDown() then
    turtle.select(1)
   else
    turtle.down()
   end
  end
 end

 if action == 6 then
  local distance = math.random(1,5)
  for i = 1,distance do
   turtle.forward()
   if turtle.detectDown() then
    turtle.select(1)
   else
    turtle.down()
   end
  end
 end

 if action == 7 then
  local distance = math.random(1,5)
  for i = 1,distance do
   turtle.up()
  end
 end

 if action == 8 then
  local distance = math.random(1,5)
  for i = 1,distance do
   turtle.down()
  end
 end
end