GUESSNUM
    ; get a random number between 1 and 100
    set target = ($random(100) + 1)    ; $r(100) gives 0-99

    ; loop until correct
    set tries = 0
    for {
        write !,"Guess the integer between 1 and 100: "
        read "",guess    ; gets input following write

        ; validate input
        if (guess?.N) && (guess > 0) && (guess < 101) {
            ; increment attempts
            set tries = tries + 1

            ; evaluate the guess
            set resp = $select(guess < target:"too low.",guess > target:"too high.",1:"correct!")

            ; display result, conditionally exit loop
            write !,"Your guess was "_resp
            quit:resp="correct!"
        }
        else {
            write !,"Please enter an integer between 1 and 100."
        }
    }    ; guess loop

    write !!,"You guessed the number in "_tries_" attempts."
    quit