function IsAnInt(input)
  result = tonumber(input) ~= nil
  return result 
end
function GetNumericInput(prompt)
  while true do
    print(prompt .. ":")
    ans = io.read()
    if IsAnInt(ans) then
      return tonumber(ans)
    end
    print("Your entry was not a number.")
  end
end
function isempty(string)
  return string == nil or string == ''
end
function GetInput(question)
  while true do
    print(question .. "?")
    ans = io.read()
    if isempty(ans) then
      print("Your entry seems empty.")
    else
      return ans
    end
  end
end
function AskToPlayAgain()
  while true do
    ans =  string.upper(GetInput("Would you like to play again? (\"YES\" or \"NO\")"))
    if ans == "YES" or ans == "Y" then
      return true
    end
    if ans == "N" or ans == "NO" then
      return false
    end
    print("Please respond with \"YES\" or \"NO\"")
  end
end
Running = true
GotMaxNumber = false
GameOver = false
MaxNumber = 0
Answer = 0
Guess = 0
Tries = 0
print("*** GUESS A NUMBER : LUA ***")
math.randomseed(os.time())
while Running == true do
  while GotMaxNumber == false do
      MaxNumber = GetNumericInput("Please enter the maximum number you wish to use")
      if MaxNumber > 0 then
        GotMaxNumber = true
        Answer = math.random(1,MaxNumber)
        GameOver = false
        Tries = 0
        print("Ok, I am thinking of a number between 1 and " .. MaxNumber)
      else
        print("The maximum number should be greater than zero.")
      end
  end
  Guess = GetNumericInput("Guess a number between 1 and " .. MaxNumber)
  Tries = Tries + 1
  if Guess > Answer then
    print("Too High.")
  end
  if Guess < Answer then
    print("Too Low.")
  end
  if Guess == Answer then
    if Tries == 1 then
      print ("You got it in 1 try!")
    else
      print ("You got it in " .. Tries .. " Tries!")
    end
    GameOver = true
  end
  if GameOver == true then
    Running = AskToPlayAgain()
    if Running == true then
      GotMaxNumber = false
    end
  end
end
print("Thanks for playing!")
print("*** GAME OVER ***")