Jquery draggable attach to new container

I have a div inside a parent div that users can drag from dropbox to final_dest. Users can also create new items with a button click. The button click appends the new div to dropbox.

<div id='#dropbox'>
      <div id='item_1'>Some Item</div>
</div>

<div id='final_dest'></div>

If a user drags item_1 to another container, how can i remove it from dropbox and put it in final_dest?

            $('#item_'+a).draggable({ // make this whole damn thing draggable
                    drag:function(event){
                            helper:"clone",
                            jsPlumb.repaintEverything();
                    },
                    stop:function(event,ui){
                                    $('this').detach('#dropbox');
                                    $('this').append('final_dest');

                    }

            });

I have tried using detach but can not figure out how to remove it from dropbox div.

The problem is if a user drags item_1 to final_dest, and then creates a new item_2 div, it appears below item_1's spot in dropbox. i am trying to get it to appear where item_1 did. It does this, because item_1 is not removed from dropbox.