title: Firefox's onInput with contentEditable inside a <span> isn't working
body: <p>I've been fooling around with onInput and contentEditable, trying to make a script that would automatically show the sum of some math. Part of the concept was to have the input grow as the user typed, which I found to work very well with a <code>&lt;span&gt;</code> tag using contentEditable. Most of the testing I did was on Google Chrome, and it seems to work there, but the onInput doesn't seem to work in Firefox (4.0). onKeyUp works in Firefox however, but isn't instant as onInput.</p>
  
  <pre><code>&lt;div id="f"&gt;
      &lt;span oninput="go()" id="p" class="x" contenteditable="true"&gt;0
      &lt;/span&gt;
      % of
      &lt;span oninput="go()" id="n" class="x" contenteditable="true"&gt;0
      &lt;/span&gt;
      =
      &lt;span id="r" class="x" contenteditable="true"&gt;0
      &lt;/span&gt;
      &lt;p id="a"&gt;&lt;/p&gt;
  &lt;/div&gt;
  
  function go() {
      p = document.getElementById('p').innerHTML;
      n = document.getElementById('n').innerHTML;
      r = document.getElementById('r');
      a = document.getElementById('a');
      r.innerHTML = p / 100 * n;
      a.innerHTML = p + "% of " + n + " equals " + p / 100 * n;
  }
  </code></pre>
  
  <p>Have a look at <a href="http://jsfiddle.net/2D6Nu/" rel="nofollow">the script over at jsFiddle</a>.</p>
  
  <p>Thanks.</p>