title: Bootstrap image popup
body: <p>I am using bootstrap and have a button:</p>
  
  <pre><code> &lt;button type="button" class="btn btn-primary"&gt;Popup image&lt;/button&gt;
  </code></pre>
  
  <p>I have an image on the same directory and would like to have it popup in some kind of overlay where the background is grey if that is possible. I am used to javascript, so normally would do something like onclick and call a function that would do it. But in bootstrap I am unsure of how to do this. Thank you</p>