gistfile1.js

 $(document).ready(function() {

        $(".box").draggable({
            revert: true
			
        });

        $(".box").droppable({
	
            activeClass: "drop-active",

            drop: function(event, ui) {
                var to = $(this).attr("id").replace("collection_","");
                var from = ui.draggable.attr("id").replace("collection_","");

				//console.log(from + to);
				window.location = host+"merge/"+from+"/with/"+to;
            }
        });

            return false;
        });