Nil [error] in RP frame door program, with GUI

Hey guys,

I wrote a program to automatically open the frame door of my hangar, and got it working. However, after implementing some code for a nice GUI (based on a program by NitrogenFingers), I receive a nil error upon trying to move the selection by pressing the "down" arrow:
startup:102: attempt to index ? (a nil value)

(hopefully) relevant part of code:

local menustate = "main"
local mopt = {
["main"] = {
  options = {"open", "close", "quit"},
  draw = drawMain
}
}
function runMenu()
while true do
  term.clear()
  drawHeader()
  mopt[menustate].draw()
  local id, key = os.pullEvent("key")
  if key == 200 and select > 1 then select = select-1
  elseif key == 208 and select < #mopt[menustate].options then select = select+1
  elseif key == 28 then
   if mopt[menustate].options[select] == "quit" then break
   end
   if mopt[menustate].options[select] == "open" then
	openSeq()
   end
   if mopt[menustate].options[select] == "close" then
	closeSeq()
   end
  end
  menustate = mopt[menustate].options[select]
end
end

Entire code in the attachment.

I have no idea what is wrong, or how to fix it, so any help would be appreciated!
Thank you, in advance, for your time!

Aerik out.

Your problem is line 131

menustate = mopt[menustate].options[select]

It's setting menustate to a menu you don't actually have in mopt

Thank you! (Feels stupid)

Aerik, on 04 June 2012 - 03:58 PM said:

Thank you! (Feels stupid)

Don't feel stupid, everyone makes mistakes, and this one was pretty well hidden :)/>/>

Had to write debug messages into the code to find it (but then, it was pretty late… :D/>/>)