Aperture Science OS Graphics - Setup Menu

--this program acts as a Graphical Overlay to make the setup process look nicer
local tArg = {...}
term.clear()
term.setCursorPos(1,1)
local w, h = term.getSize()
local Stage = 0
local Version_1 = "1.0"
local Version_2 = "2.0"
local Version_3 = nil

function CenterText(y,text)
  local x = math.floor((w - string.len(text)) /2)
  term.setCursorPos(x,y)
  term.clearLine()
  term.write(text)
end

function SlowCenterText(y,text)
  local x = math.floor((w - string.len(text)) /2)
  term.setCursorPos(x,y)
  term.clearLine()
  textutils.slowWrite(text)
end

function DrawBackground()
term.clear()
term.setCursorPos(1,1)
paintutils.drawFilledBox(1,1,w,h,colors.blue)
paintutils.drawBox(1,1,w,h,colors.gray)
paintutils.drawPixel(2,2,colors.red)
end

function DrawMenu()
CenterText(2,"--Setup---Menu--")
term.setCursorPos(1,3)
if Stage == 0 then
  print("SYSTEM SETUP")
  print("Please Enter your desired version")
  print("1 - "..Version_1)
  print("2 - "..Version_2)
  print("3 - "..Version_3)
  SetupInteraction_1()
elseif Stage == 1 then
  print("Starting Security Search")
  print("please wait while your ComputerCraft Device is searched")
  print("For any Harmful or insecure Programs")
  CenterText(7,"Security Search")
  SlowCenterText(8,"Searching...Searching...Searching...")
  sleep(1)
  DrawBar(2,10,0.05)
  sleep(2)
  DrawBar(2,10,0.1)
  sleep(1)
  DrawBar(2,10,0.35)
  sleep(2)
  DrawBar(2,10,0.60)
  sleep(4)
  DrawBar(2,10,0.9)
  sleep(2)
  DrawBar(2,10,1)
  sleep(1)
  Centertext(11,"Completed!")
  sleep(2)
  Stage = 2
elseif Stage == 2 then

elseif Stage == 3 then

end
if Stage < 4 then
  DrawBackground()
  DrawMenu()
end
end

function DrawBar(x,y,Progress)
local Position = (w-x)*Progress
paintutils.drawFilledBox(x,y,Position-x,y+3,colors.green)
end

function SetupInteraction_1()
while true do
  local event, key = os.pullEvent("key")
  if key == keys.one then

    break
  elseif key == keys.two and Version_2 ~= nil then

    break
  elseif key == keys.three and Version_3 ~= nil then

    break
  end
end
end


if tArg[1] == "Start" then
  Stage = 0
elseif tArg[1] == "Finished" then
  Stage = 3
end
DrawBackGround()
DrawMenu()