Logon Sys 1.1

w,h = term.getSize()
local menustate = "Logon Program"
local user = ""

function isInteger(nIn)
    if math.floor(nIn) == nIn then return true
    else return false end
end
function printCentred(str , h)
  term.setCursorPos(w/2 - #str/2, h)
  term.write(str)
end
function printRight(str , h)
  term.setCursorPos(w - #str, h)
  term.write(str)
end
function printLeft(str , h)
  term.setCursorPos(1, h)
  term.write(str)
end

function returnFileAsTable(aFile) --This function and the two bellow it are credit of Challenge.Accepted on the ComputerCraft Forums
    f= fs.open(aFile,"r")
    aTable = {}
    aLine = f.readLine()
    while aLine ~= nil do
        table.insert(aTable, aLine)
        aLine = f.readLine()
    end
    return aTable
end
function seperateString(aString, sep)
    p = string.find(aString, sep)
    return string.sub(aString, 1, p-1), string.sub(aString, p+1)
end
function iterateTable(aTable)
    local keyTable = {}
    local definitionTable = {}
    for i=1, #aTable do
        key, def = seperateString(aTable[i], ":")
        table.insert(keyTable, key)
        table.insert(definitionTable, def)
    end
    return keyTable, definitionTable
end

function drawHeader()
  term.setTextColour(colours.white)
  printCentred("KYLEOS - TEST 1.0", 1)
  printLeft(string.rep("-",w),2)
  printLeft(string.rep("-",w),h-1)
  printLeft(menustate.." : "..user,h)
  printRight("made by kylergs",h)
end

function drawLogon()
  printCentred("Please LogOn to your user", 5)
  printCentred("Username: ",8)
  printCentred("Password: ",10)
end

function drawLog(acc)
    term.clear()
    if acc then
        drawHeader()
        printCentred("Logon Accepted", 6)
        printCentred("Logging on to - "..user, 8)
        printCentred(" Press any Key to continue...  ", 11)
    else
        drawHeader()
        printCentred("Logon Denied", 6)
        printCentred("Reseting to guest",8)
        printCentred("Press any Key to continue", 11)
        user = "guest"
    end
    os.pullEvent("key")
    sleep(0.1)
end

function logon(users,cUser)
    local usr
    user = cUser
    local pass
    term.clear()
    drawHeader()
    drawLogon()
    term.setCursorPos(w/2+5,8)
    usr = read()
    term.setCursorPos(w/2+5,10)
    inpass = read("*")
    flag = false
    if users[usr] then
        if users[usr].pass == inpass then
            user = usr
            drawLog(true)
        else
            drawLog(false)
        end
    else
        drawLog(false)
    end
 return user
end