title: CSS Expressions
body: <p>I read somewhere that CSS Expressions were deprecated and shouldn't even be used.  I had never heard of them and decided to take a look.  I found a code example that kept a floating element in the same spot on the screen, even if you scrolled.</p>
  
  <pre><code>&lt;html&gt;
  &lt;style&gt;
  #fixed {
  position:absolute;
  left:10px;
  top:expression(body.scrollTop + 50 + "px");
  background:white;
  border:1px solid red;}
  &lt;/style&gt;
  &lt;body&gt;
  &lt;p id="fixed"&gt;Here is some text, which is fixed.&lt;/p&gt;
  &lt;p&gt;
  [many times: "stuff &lt;br/&gt;"]
  &lt;/p&gt;
  &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>This reminded me of the sites that had the "share bars" and stuff at the bottom of their pages.</p>
  
  <p>So...</p>
  
  <ol>
  <li>Is this how they are doing it?</li>
  <li>Is it alright to use Expressions in this situation?</li>
  <li>If not, what should I use?</li>
  <li>Are there any other interesting/helpful things that expressions can help with?</li>
  </ol>