select2/docs/_includes/examples/basics.html

<section>

  <h1 id="basic">The basics</h1>

  <p>
    Select2 can take a regular select box like this...
  </p>

  <p>
    <select class="js-states form-control"></select>
  </p>

  <p>
    and turn it into this...
  </p>

  <div class="s2-example">
    <p>
      <select class="js-example-basic-single js-states form-control"></select>
    </p>
  </div>

  <pre class="code" data-fill-from=".js-code-basic"></pre>

<script type="text/x-example-code" class="js-code-basic">
$(document).ready(function() {
  $(".js-example-basic-single").select2();
});

<select class="js-example-basic-single">
  <option value="AL">Alabama</option>
    ...
  <option value="WY">Wyoming</option>
</select>
</script>

</section>