Linux OS

--Bootup
print("LINUX OS V1.0")
sleep(0.6)
textutils.slowPrint("######################")
sleep(0.9)
--Log In
while true do
term.clear()
term.setCursorPos(1, 1)
print("User:")
input = read("X")
if input == "Karol" then
 while true do
 term.clear()
 term.setCursorPos(1, 1)
 print("Password:")
 input = read("X")
 if input == "Carlito2006" then
--System
  term.clear()
  term.setCursorPos(1,1)
  term.setBackgroundColor( colors.green )
  textutils.slowPrint("Welcome, User!")
  texutils.slowPrint("What do you want to do?")
--ButtonAPI
local button={}

function clearTable()
   button = {}
end

function setTable(name, func, param1, param2, active, xmin, xmax, ymin, ymax)
   button[name] = {}
   button[name]["func"] = func
   button[name]["active"] = active
   if active == nil then
     active = false
   end
   button[name]["param1"] = param1
   button[name]["param2"] = param2
   button[name]["xmin"] = xmin
   button[name]["ymin"] = ymin
   button[name]["xmax"] = xmax
   button[name]["ymax"] = ymax
end

function remTable(name)
  button[name] = {}
  button[name]["xmin"] = 0
  button[name]["ymin"] = 0
  button[name]["xmax"] = 0
  button[name]["ymax"] = 0
end


function fill(text, color, bData)
   mon.setBackgroundColor(color)
   local yspot = math.floor((bData["ymin"] + bData["ymax"]) /2)
   local xspot = math.floor((bData["xmax"] - bData["xmin"] - string.len(text)) /2) +1
   for j = bData["ymin"], bData["ymax"] do
      mon.setCursorPos(bData["xmin"], j)
      if j == yspot then
         for k = 0, bData["xmax"] - bData["xmin"] - string.len(text) +1 do
            if k == xspot then
               mon.write(text)
            else
               mon.write(" ")
            end
         end
      else
         for i = bData["xmin"], bData["xmax"] do
            mon.write(" ")
         end
      end
   end
   mon.setBackgroundColor(colors.black)
end

function screen()
   local currColor
   for name,data in pairs(button) do
      local on = data["active"]
      if on == true then currColor = colors.lime else currColor = colors.red end
      fill(name, currColor, data)
   end
end

function toggleButton(name)
   button[name]["active"] = not button[name]["active"]
   screen()
end

function flash(name)
   toggleButton(name)
   screen()
   sleep(0.15)
   toggleButton(name)
   screen()
end

function checkxy(x, y)
   for name, data in pairs(button) do
      if y>=data["ymin"] and  y <= data["ymax"] then
         if x>=data["xmin"] and x<= data["xmax"] then
            if data["param1"] == "" then
              data["func"]()
            else
              data["func"](data["param1"], data["param2"])
            end
	    return true
         end
      end
   end
   return false
end

function heading(text)
   w, h = mon.getSize()
   mon.setCursorPos((w-string.len(text))/2+1, 1)
   mon.write(text)
end

function label(w, h, text)
   mon.setCursorPos(w, h)
   mon.write(text)
end
  end
end
end
end