Duplicates after Drop

Duplicates after Drop


Hello.
I have problem with drag'n'drop. When I drop element I create text
(for sample) in drop zone. But instead of one string, I have two
strings. It's very strange and I can't understand why it's happens.
$(".draggable").draggable({helper:'clone', zIndex:1000});
    $("#dropzone").droppable({
            accept: '.draggable',
            activeClass: 'droppable-active',
            hoverClass: 'droppable-hover',
            tolerance: 'touch',
            drop: function(ev, ui) {
                var el = $(ui.draggable.element).clone();
                $(this).append($(document.createElement('div')).text($
(ui.draggable.element).attr("src")));
            }
        });
Here my code. Thanks!