jquery-ui "help: clone" not running on iphone , what should i do .

Question

this is my code:

<div class="demo" style="margin:0 auto;height: 100%;">
    <div id="A" style="float:left;height:50%;margin:0 100px 0 0;width:100%;background:#333;">

    </div>
    <div id="droppable" >
        <p>Drop here</p>
    </div>
</div><!-- End demo -->

<script type="text/javascript" src="jquery-1.4.2.min.js"></script>
<script type="text/javascript" src="jquery-ui-1.8rc3.custom.min.js"></script>
<script type="text/javascript">
$(function() {
    var f=  '<div id="draggable">'+
                '<p>Drag me to my target</p>'+
            '</div>'
    $(f).appendTo($('#A'))
    $("#draggable").draggable({
        helper: 'clone'
    });
    $("#droppable").droppable({
        greedy: true,
        drop: function(event, ui) {
            //$(this).find('p').html('Dropped!');
            $(this).append($(ui.helper).draggable("disable").addClass('end').find('p'))
            $(ui.helper ).remove()
        }
    });

});
</script>

it can be running on firefox ,

but can not be running on iphone , so

what should i do ..

thanks