all-in-one-event-calendar/public/admin/base_page.php

<div class="wrap">

    <h2><?php echo $page->title; ?></h2>

    <div id="poststuff">

        <form method="post" action="">
            <?php wp_nonce_field( 'update', 'simple_page_nonce' ); ?>

            <div class="metabox-holder">
                <div class="post-box-container left-side timely">
                    <?php $template_adapter->display_meta_box( $page->meta_box_id, 'left-side', null ); ?>
                </div>
            </div>
        </form>

    </div><!-- #poststuff -->

</div><!-- .wrap -->