Computercraft reactor controller

TimeMultiplier = 60
CycleTime = 45
CooldownTime = 1

function turnOn() rs.setOutput("back", true) end
function turnOff() rs.setOutput("back", false) end
while true do

print("How many cycles should run?")
write("Cycles> ")
numCycles = read()

for i=1,numCycles do
 term.clear()
 term.setCursorPos(1, 1)
 print("+-----------------------------------------------+")
 print("|               Refuel Reactor                  |")
 print("|         Press ENTER when refueled             |")
 print("+-----------------------------------------------+")
 --[[while true do
  event, arg = os.pullEvent()
  if event == "key" and arg == 28 then break end
 end--]]
 term.clear()
 term.setCursorPos(1, 1)
 print("+-----------------------------------------------+")
 print("|             Reactor is running                |")
 print("|               Time Left:                      |")
 print("+-----------------------------------------------+")
 turnOn()
 timeleft = CycleTime
 for i=1, CycleTime do
  if timeleft < 10 then CT = tostring(timeleft).." " else CT = tostring(timeleft) end
  term.setCursorPos(1, 3)
  term.clearLine()
  print("|               Time Left: "..CT.."                   |")
  sleep(TimeMultiplier)
  timeleft = timeleft-1
 end
 turnOff()
 term.clear()
 term.setCursorPos(1, 1)
 print("+-----------------------------------------------+")
 print("|            Reactor is cooling down            |")
 print("|               Time Left:                      |")
 print("+-----------------------------------------------+")
 timeleft = CooldownTime
 if CooldownTime ~= 0 then
  for i=1, CooldownTime do
   if timeleft <10 then CdT = tostring(timeleft).." " else CdT = tostring(timeleft) end
   term.setCursorPos(28, 3)
   print(CdT.."                   |")
   sleep(TimeMultiplier)
   timeleft = timeleft-1
  end
 end
end
end