title: Display temporary image until an image are loaded
body: <p>I want to display temporary image in an HTML page until original image is loaded. How can I do that?</p>
  
  <pre><code>&lt;!-- IMG --&gt;
  &lt;img src="original.jpg" temporary-img="temp.jpg"/&gt; &lt;!-- i have no idea how to do that ! --&gt;
  </code></pre>