Rails spinoffs - Oct 2005 - restricting movement in sortable list

Hello,

I''d like to know if this is possible. Say you have a sortable list like
so:

<ul id="mysort">
   <li>one</li>
   <li>two</li>
   <li>three -- A</li>
   <li>four</li>
   <li>five -- B</li>
</ul>

Is there any way to restrict the movement of "three -- A" and
"five --
B" such that they never cross? For example, you could click on five
and move it above four but you wouldn''t be able to move it above
three. That make sense? I looked over the code and didn''t see an
obvious way to do this -- any ideas?

Thanks,
--Bill