How to add drag and drop functionalities to a div inside option panel

3 steps:

php

<?php
wp_enqueue_script( 'jquery-ui-sortable');

html

<div class="metabox-holder">
   <div class="postbox-container">
    <div id="my_div" class="meta-box-sortables ui-sortable">
        <div class="postbox" id="el1">
            <h3 class="hndle"><span>title2</span></h3>
            <div class="inside">content1</div>
        </div>
        [...elements...]
        <div class="postbox" id="el20">
            <h3 class="hndle"><span>title20</span></h3>
            <div class="inside">content1</div>
        </div>
    </div>
</div>

javascript

<script type="text/javascript">
jQuery(document).ready(function(){
    jQuery('#my_div').sortable();
});