<!DOCTYPE HTML>
<html>
  <head>
    <meta http-equiv="content-type" content="text/html; charset=utf-8">

    <title>perfect-scrollbar example</title>
    <link href="../src/perfect-scrollbar.css" rel="stylesheet">
    <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.10.2/jquery.min.js"></script>
    <script src="../src/jquery.mousewheel.js"></script>
    <script src="../src/perfect-scrollbar.js"></script>
    <style>
      #description {
        border: 1px solid gray;
        height:150px;
        width: 400px;
        overflow: hidden;
        position: relative;
      }
      #status {
        color: red;
      }
    </style>
    <script type="text/javascript">
      $(document).ready(function ($) {
        var $container = $('#description');
        var $status = $('#status');
        $container.perfectScrollbar();
        $container.scroll(function(e) {
          if($container.scrollTop() === 0) {
            $status.text('it reaches the top!');
          }
          else if ($container.scrollTop() === $container.prop('scrollHeight') - $container.height()) {
            $status.text('it reaches the end!');
          } else {
            $status.text('');
          }
        });
      });
    </script>
  </head>
  <body>
    <div id="description" class="wrapper">
      <p>Hello, world! 0</p>
      <p>Hello, world! 1</p>
      <p>Hello, world! 2</p>
      <p>Hello, world! 3</p>
      <p>Hello, world! 4</p>
      <p>Hello, world! 5</p>
      <p>Hello, world! 6</p>
      <p>Hello, world! 7</p>
      <p>Hello, world! 8</p>
      <p>Hello, world! 9</p>
    </div>
    <div id="status">
    </div>
  </body>
</html>

Add an example about the callback to check if it reaches the end.
Add an example about the callback to check if it reaches the end.
