JavaScript Guessing Game

<!DOCTYPE html>
<html>

  <head>
    <title>JavaScript Guessing Game</title>
    <link rel="stylesheet" href="style.css">
    <script src="app.js"></script>
  </head>

  <body>
    <h1>JavaScript Guessing Game</h1>
    <p>
      <button onclick="setup()">Pick a secret number!</button>
    </p>
    <p>
      <button onclick="play()">Guess my secret number!</button>
    </p>
  </body>

</html>

var secret_number = 0;
function setup() {
  secret_number = prompt("What's the secret number?");
}

function play() {
  var guess;
  guess = prompt("What's your guess?");
  if (guess > secret_number) {
      alert("Too high!");
  } else if (guess < secret_number) {
      alert("Too low!");
  } else {
      alert("Correct! The secret number is " + secret_number + "!");
  }
}