The game makes a random 5 digit secret number, with all 5 digits different, e.g. 41792, 08327 etc. You type in a 5 digit number also with all digits different (and click the Guess button), and in reply you are told how many digits you have right, and how many of them are in the right position. E.g. if you guess 12345 and the secret number is 37642, you will be told 3 right with 1 in the right position. You keep guessing until you get the secret number (though after 40 goes you will be told the number). To start the game, type your first guess in the box and click on "Guess".
