Sidebar disappears when I add widget code

Trying to add this code to my sidebar.php to add the vSlider plugin for site pdxandroid.com. When I add it the whole sidebar disappears. Is there a special place where I need to add the code or move somethings around to make it work?

<div id="sidebar">
        <ul>
            <?php   /* Widgetized sidebar, if you have the plugin installed. */
                    if ( !function_exists('dynamic_sidebar') || !dynamic_sidebar() ) : ?>
            <li>
                <!-- You can put here the vSlider call -->
                <?php if (function_exists('vSlider')) { vSlider(); }?>
            </li>
        </ul>