title: How to mimic Wordpress "Widget" drag & drop behavior?
body: <p>I need to mimic Wordpress "Widget" drag &amp; drop behavior. <a href="http://jqueryui.com/demos/sortable/#portlets" rel="nofollow">jQuery UI Sortable</a> can do it but not the same way as WP.</p>
  
  <p>I can drag &amp; drop now but the dropped element is removed from the source. That's not what I expected. </p>
  
  <p>Let's say I have two <code>&lt;ul&gt;</code> A and B. I drag an item of A and drop it to B and I expect the item stay within A, not to be removed from it. </p>
  
  <p>Any idea? I really appreciate your helps!</p>