title: How to change the opacity of image on hover using css
body: <p>I'm trying to figure out how to set all images to be <strong>50% opacity initially</strong>, and then change to <strong>100% opacity on hover</strong>.</p>
  
  <p>I tried setting this rule in the <code>.css</code> file but it gives a parse error:</p>
  
  <pre><code>img {
    opacity:0.4;
    filter:alpha(opacity=40); 
  }
  img:hover {
    opacity:1.0;
    filter:alpha(opacity=100); 
  }
  </code></pre>