title: setting the 50% of original picture width and height using css
body: <p>is there any way of setting the 50% of original picture width and height using css? 
  for example i have this code:</p>
  
  <pre><code>    &lt;img src="http://content.captive-portal.com/files/ign/movie-news/content/2b.jpg"&gt;
  </code></pre>
  
  <p>I don't specify any width and height in html, but I want it to be 50% of the original height and width. Can I use CSS to do that?</p>
  
  <p>this doesn't work:</p>
  
  <pre><code>img{width:50%; height:50%}
  </code></pre>
  
  <p>Is there any way to overcome this?
  Thanks</p>