title: Bootstrap alert will not show
body: <p>I have converted a page from BS2 to BS3 and I can't get the alert to show on a diaglog. I have shrunk it down to a simple example. I must be missing something basic and obvious!</p>
  
  <pre><code>&lt;div class="alert alert-danger hide" id="form-error"&gt;
      &lt;button type="button" class="close" data-dismiss="alert" aria-hidden="true"&gt;
          &amp;times;
      &lt;/button&gt;
  &lt;/div&gt;
  
  
  &lt;a href="#" class="btn btn-primary btn-large" type="button" onclick="mysavefunction()" id="trev"&gt;Press me&lt;/a&gt;
  </code></pre>
  
  <p>Save looks like this</p>
  
  <pre><code>$('#form-error').html("&lt;p&gt;error message").show(); 
  </code></pre>
  
  <p><a href="http://jsfiddle.net/GrimRob/v5sqcrLr/21/" rel="nofollow">http://jsfiddle.net/GrimRob/v5sqcrLr/21/</a></p>