PHP: WordPress Slides v2

wp-slides.php

<?php
$args = array(
    'post_type'      => 'slides', // custom post type
    'orderby'        => 'menu_order',
    'posts_per_page' => -1
);

$slides = new WP_Query( $args );

if ( $slides->have_posts() ) : $count = 0; ?>
    <ul class="slides">

        <?php while ( $slides->have_posts() ) : $slides->the_post(); $count++; ?>
            <li id="slide-<?php echo $count; ?>" class="slide">
                <?php if ( has_post_thumbnail() ) the_post_thumbnail( 'slide' ); // custom thumbnail size ?>

                <div class="slide-content">
                    <h2><?php the_title(); ?></h2>
                    <?php the_content(); ?>
                </div>
            </li>
        <?php endwhile; ?>

    </ul>
<?php endif; ?>