title: jquery UI draggable + sortable (cancel receive)
body: <p>My scenario is I have a list of items that are draggable but not sortable and another list that is sortable. What I want to achieve is to drag from the draggable into the sortable but when I drop the item into the sortable I want to make an ajax request and depending on the answer to insert the item into the sortable or not. 
  I tried to use on beforeStop or receive events for the sortable to cancel the item being added to the sortable but didn't find a solution.
  I made a jsfiddle here <a href="http://jsfiddle.net/5pTCd/21/" rel="nofollow">http://jsfiddle.net/5pTCd/21/</a></p>