List
 <ul id="selectable">
                <li class="ui-widget-content" id="Magic Mouse">Magic Mouse</li>
                <ul>
                    <li class="ui-widget-content" id="News">News</li>
                    <li class="ui-widget-content">ToDo</li>
                </ul>
                <li class="ui-widget-content">Articles</li>
                <ul>
                    <li class="ui-widget-content">Android</li>
                    <ul>
                        <li class="ui-widget-content">Barcode</li>
                    </ul>
                </ul>

JavaScript

<script type="text/javascript" language="javascript">

        $(document).ready(function () {

            $(".ui-widget-content").click(function () {
                $(this).addClass("ui-selected").siblings().removeClass("ui-selected");
            });

        });
    </script>

List
 <ul id="selectable">
                <li class="ui-widget-content" id="Magic Mouse">Magic Mouse</li>
                <ul>
                    <li class="ui-widget-content" id="News">News</li>
                    <li class="ui-widget-content">ToDo</li>
                </ul>
                <li class="ui-widget-content">Articles</li>
                <ul>
                    <li class="ui-widget-content">Android</li>
                    <ul>
                        <li class="ui-widget-content">Barcode</li>
                    </ul>
                </ul>

JavaScript

  <script type="text/javascript" language="javascript">

        $(document).ready(function () {

            $(".ui-widget-content").click(function () {
$('*').removeClass("ui-selected");
                $(this).addClass("ui-selected");
            });

        });
    </script>