that one door program that i can't fix

--[[
  this code is poorly optimised and written.
  the functionality of this code is to controll doors. that's it. nothing special.
  future improvements include: larger buttons, key disk support and password support all of which i can do myself.
  reffer to line 42 for detailed info on my issues...
]]

term.clear()
term.setCursorPos(1,1)

local oldBgC = term.getBackgroundColor()
local BgC = colors.red
local sOut = false

local w,h = term.getSize()

while true do

--defining button color
local out = rs.getOutput("bottom")
 if out then
  BgC = colors.green
 else
  BgC = colors.red
 end

--button "write"
term.setCursorPos(1,1)
term.clearLine()
term.setCursorPos(2,2)
term.setBackgroundColor(BgC)
term.write(" ")
term.setBackgroundColor(oldBgC)

--button "handeler"
local event, mb, x, y = os.pullEvent("mouse_click")
 if x == 2 and y == 2 then
   sOut = not out
 end
rs.setOutput("bottom",sOut)

--here's where i'm stuck;
--calling exit() causes the program to halt until it's satisfied or errors.
--parallel imo isn't what i'd need rather coroutines.
--but i can't, for the life of me, get them to cooperate dispite
--the lua 5.1, 5.3 manual refferancing.
--all i need help with is getting an input field at the very bottom to be able to
--pass comands and args to the program while still pulling mouse_click events

--exit "handeler"
function exit()

 term.setCursorPos(1,h-2)
 term.clearLine()
 term.setCursorPos(1,h-1)
 term.write('type "exit()" to exit')
 term.setCursorPos(1,h)

  if read() == "exit()" then
   ex = true
  end
end

if ex == true then break end

--debug, ignore this
--[[
local w,h = term.getSize()
term.setCursorPos(1,h)
term.clearLine()
print("cordinates> "..x..","..y)

term.setCursorPos(1,7)
term.clearLine()
--]]
end