Sudden issue with my plugin

I want to create a Wordpress plugin, but after replacing a few words with Notepad, the whole plugin won't show up anymore. I have tried checking all lines, reverting it back to what it was, nothing. It's dead! I hope someone can help me out, this really frustrates me.

<?php
function em_settings_page() {
    global $em_options;

    $selected_page = ! empty( $em_options['page'] )         ? $em_options['page']         : 0;
    ?>
    <div class="wrap">
        <div id="upb-wrap" class="upb-help">
            <h1><?php
            $maintenance = __('Maintenance');
            $settings = __('Settings');
            echo "$maintenance $settings";
            ?></h1>
            <?php
            if ( ! isset( $_REQUEST['updated'] ) )
                $_REQUEST['updated'] = false;
            ?>
            <?php if ( false !== $_REQUEST['updated'] ) : ?>
            <div class="updated fade"><p><?php _e( 'Options saved' ); ?></p></div>
            <?php endif; ?>
            <form method="post" action="options.php">
            <table class="form-table">
                <?php settings_fields( 'em_settings_group' ); ?>
            <tr>
                <td><strong><?php echo __('Enabled'); ?></strong></td>
                <td><input id="em_settings[enable]" class="js_enabled" name="em_settings[enable]" type="checkbox" value="1" <?php checked( true, isset( $em_options['enable'] ) ); ?>/></td>
            </tr>
            <tr>
                <td><strong><?php echo __('Page'); ?></strong></td>
                <td>
                    <?php $pages = get_pages(); ?>
                    <select id="em_settings[page]" name="em_settings[page]">
                        <?php foreach($pages as $page) { ?>
                            <option value="<?php echo esc_attr( $page->ID ); ?>" <?php if( $selected_page == $page->ID ) { echo 'selected="selected"'; } ?>><?php echo $page->post_title; ?></option>
                        <?php } ?>
                    </select>
                </td>
            </tr>
            <tr>
                <td></td>
                <td><input type="submit" class="button-primary" value="<?php _e( 'Save' ); ?>" /></td>
            </tr>
            </table>
            </form>
        </div>
    </div>
    <?php
}

function em_register_settings() {
    register_setting( 'em_settings_group', 'em_settings' );
}
add_action( 'admin_init', 'em_register_settings' );


function em_settings_menu() {
    add_submenu_page('options-general.php', __('Maintenance'), __('Maintenance'),'manage_options', 'maintenance', 'em_settings_page');
}
add_action( 'admin_menu', 'em_settings_menu' );

function maintenance_stylesheet() {
        ?>
    <style type="text/css">
    #wpadminbar #wp-admin-bar-maintenance {background-color:#c30000;}
    #wpadminbar #wp-admin-bar-maintenance a {font-weight:bold;}
    </style>
<?php
}
add_action('admin_head', 'maintenance_stylesheet');

if($em_options['enable'] == "1") {
    function create_maintenance_menu() {
        global $wp_admin_bar;

        $menu_id = 'maintenance';
        $wp_admin_bar->add_menu(array(
            'id' => $menu_id,
            'title' => __('Maintenance'),
            'href' => 'options-general.php?page=maintenance'
            ));
    }
    add_action('admin_bar_menu', 'create_maintenance_menu', 2000);
}
?>

So the issue is that the whole settings page isn't showing up anymore in the left sidebar of the admin backend.

via Chebli Mohamed