title: Css Content, Attr and Url in the same sentence
body: <p>I have used the <em>content attribute</em> for a long time, and today I wanted to try something new. Instead of using JS to display a image tooltip I wanted to know if it was possible to do it dynamically with CSS.</p>
  
  <p>So I tried:</p>
  
  <pre><code>.TableLine:hover:after{
    content: url("../Img/Photo/"attr(id)".jpg"); 
  }
  </code></pre>
  
  <p>where <code>attr(id)</code> is supposed to return the ID of the picture (alphanumeric) which is also the name of the picture.</p>
  
  <p>It doesn't work at all, it has no effect. I think that the block did not parse because adding a border or background to the block also seems to have no effect.</p>
  
  <p>When I just use the <code>attr(id)</code> alone, without the url thing, it works perfectly. It also works when I replace <code>attr(id)</code> with the real name of the picture.</p>
  
  <p>After searching a while on the web I haven't found anything relevant so here I am.  Is that a known bug or just my mistake? :)</p>