To further simplify our work, we're going to create a set_scene function which will take the scene number as input. So for the previous page you would simply have added the following to your index.html.

  <script>
    set_scene(16);
  </script>
</body>

See how far you can get before looking at my work.

My index.html
<html>
<head>
<title>Rainbow</title>
<link rel='stylesheet' href='styles.css'>
<script src='library.js'></script>
<script src='set_scene.js'></script>
</head>
<body>
  <div id='game'>
    <img src='images/scenes/3.jpg' id='scene'>
    <img src='images/shapes/blue.png' id='blue' class='item'>
    <img src='images/shapes/green.png' id='green' class='item'>
  </div>
  <script>
    set_scene(16);
  </script>
</body>
</html>