title: How to force a user to choose a <select> option with bootstrap
body: <p>I've been trying to work the answer out to this for hours and it's driving me insane!</p>
  
  <p>I'm using Twitter Bootstrap and bootstrap-min.js.</p>
  
  <p>Here is my code:</p>
  
  <pre><code>&lt;select id="assettype" name="assettype" class="input-medium required"&gt;
     &lt;option&gt;-- Please select --&lt;/option&gt;
     &lt;option value="1"&gt;Printer&lt;/option&gt;
     &lt;option value="2"&gt;Scanner&lt;/option&gt;
  &lt;/select&gt;
  </code></pre>
  
  <p>If a user leaves the form as the '-- Please select --' option then I want an error to prevent the user from submitting the form i.e. forcing them to make a selection.</p>
  
  <p>Any help would be massively appreciated! Thanks in advance.</p>