Twitter Bootstrap inline input with dropdown

I'm trying to display a text input inline with a dropdown button. I can't figure out how to do this though. Here's the HTML I've tried (I've put all of it on a single line with no results):

<div class="input-append">
  <input type="text" placeholder="foo" class="input-mini">
  <div class="btn-group">
    <a id="amount_type" class="btn dropdown-toggle" data-toggle="dropdown" href="#">10<span class="caret"></span></a>
    <ul id="amount_type_options" class="dropdown-menu">
      <li class="selected"><a href="#">10</a></li>
      <li><a href="#">100</a></li>
      <li><a href="#">1000</a></li>
    </ul>
  </div>
</div>

Is this possible?

Thank you