title: How is mousemove handled in IE8 and previous?
body: <p><a href="http://www.quirksmode.org/dom/events/mousemove.html" rel="nofollow">http://www.quirksmode.org/dom/events/mousemove.html</a> has mousemove events handled on IE8 for document but not window, but I presently have:</p>
  
  <pre><code>    try
          {
          document.onmousemove = drag.on_mouse_move;
          }
      catch(error)
          {
          if (typeof document.attachEvent !== undefined)
              {
              document.attachEvent("onmousemove", drag.on_mouse_move);
              }
          }
  </code></pre>
  
  <p>The first real statement throws an error in IE8, as does the last statement. The latter error claims a type mismatch; the former error throws "Not implemented."</p>
  
  <p>How can/should I register a mousemove event listener in IE8(/7/6)?</p>