bootstrap rating toggle btn-group

HTML

<link rel="stylesheet" href="http://twitter.github.com/bootstrap/assets/css/bootstrap.css">
<script src="http://twitter.github.com/bootstrap/assets/js/bootstrap-button.js"></script>
<form>
    <input type="text" name="email" value="username" />
<div class="btn-group" data-toggle="buttons-radio">
  <button class="btn" type="button" name="rating" value="1">
    1
  </button>
  <button class="btn" type="button" name="rating" value="2">
    2
  </button>
  <button class="btn" type="button" name="rating" value="3">
    3
  </button>
  <button class="btn" type="button" name="rating" value="4">
    4
  </button>
</div>

<button class="btn" type="submit" name="submit">Submit</button>
</form>