local side = "left"      -- Set the side for the redstone output
local userinput = ""     -- Initialize user input
local event = ""         -- Initialize event

redstone.setOutput(side, false)    -- Clear output, just in case.

while true do

-- First part of the loop, lamp is off.
  term.clear()                       -- clear the screen
  term.setCursorPos(1,1)             -- Put the cursor at the top left corner.
  print("To turn lamp on, press L.")
  print("To exit, press any other key.")

-- Wait for user input (as a character), convert it to uppercase.
  event, userinput = os.pullEvent("char")
  userinput = string.upper(userinput)

-- Check to see if the input is an L, otherwise, break the loop.
  if userinput == "L" then
    redstone.setOutput(side, true) -- Turn on the redstone output
  else
    term.clear()
    break
  end

  term.clear()                     -- clear the screen
  term.setCursorPos(1,1)           -- Put the cursor at the top left corner
  print("To turn lamp off, press L.")
  print("To exit, press any other key.")

-- Wait for user input (as a character), convert it to uppercase.
  event, userinput = os.pullEvent("char")
  userinput = string.upper(userinput)

-- Check to see if the input is an L, otherwise, break the loop.
  if userinput == "L" then
    redstone.setOutput(side, false) -- Turn off the redstone output
  else
    term.clear()
    break
  end

end -- End of while true loop.