run = 0

function listen()
 while true do
  if run = 0 then
	print "Press any key to continue"
	os.pullEvent("key")
	run = 1
  end
  else if run = 1 then
	print "Press any key to pause after current cycle"
	os.pullEvent("key")
	run = 0
  end
 end
end

function main_loop()
 while run = 1 do
  --do your other stuff in here
 end
end

--end of file run everything
parrallel.waitForAll(listen, main_loop)