loop-grid.php / grab first image

<?php
/**
 * The loop to show posts in columns
 *
 * loop-grid.php

 * @package WordPress
 * @subpackage Twenty Ten
 * @since 3.0.0
 */
?>
 <?php global $query_string; query_posts( $query_string .'&posts_per_page=40'); //set number of posts ?>
<?php /* Display navigation to next/previous pages when applicable */ ?>
<?php if ( $wp_query->max_num_pages > 1 ) : ?>
        <div id="nav-above" class="navigation">
        <?php if( function_exists('wp_pagenavi') ) :
wp_pagenavi();
else : ?>
                <div class="nav-previous"><?php next_posts_link( __( '<span class="meta-nav">&larr;</span> Older posts', 'twentyten' ) ); ?></div>
                <div class="nav-next"><?php previous_posts_link( __( 'Newer posts <span class="meta-nav">&rarr;</span>', 'twentyten' ) ); ?></div>
        <?php endif; ?>
        </div><!-- #nav-above -->
<?php endif; ?>

<?php /* If there are no posts to display, such as an empty archive page */ ?>
<?php if ( ! have_posts() ) : ?>
        <div id="post-0" class="post error404 not-found">
                <h1 class="entry-title"><?php _e( 'Not Found', 'twentyten' ); ?></h1>
                <div class="entry-content">
                        <p><?php _e( 'Apologies, but no results were found for the requested Archive. Perhaps searching will help find a related post.', 'twentyten' ); ?></p>
                        <?php get_search_form(); ?>
                </div><!-- .entry-content -->
        </div><!-- #post-0 -->
<?php endif; ?>

<?php /* Start the Loop */ ?>


<?php $num_cols = 5; // set the number of columns here

for ( $i=1 ; $i <= $num_cols; $i++ ) :
echo '<div id="col-' . $i . '" class="col" >';
$counter = $num_cols + 1 - $i; ?>

<?php while (have_posts()) : the_post();
if( $counter%$num_cols == 0 ) :
// begin of core posts output ?>


<?php $bg_img = wp_get_attachment_image_src( get_post_thumbnail_id($post->ID) ); ?>
<?php $bg_img = esc_attr($bg_img[0]); ?>
<?php if( !$bg_img ) { $bg_img = get_first_image(); } //if ther is no featured image, try to get the first image from the post ?>
             <div id="post-<?php the_ID(); ?>" <?php post_class(); ?> <?php if( $bg_img ) { echo ' style="background-image: url(' . $bg_img . '); "'; } ?>>
                        <h2 class="entry-title"><a href="<?php the_permalink(); ?>" title="<?php printf( esc_attr__( 'Play %s', 'twentyten' ), the_title_attribute( 'echo=0' ) ); ?>" rel="bookmark"><span><?php the_title(); ?></span></a></h2>







                </div><!-- #post-<?php the_ID(); ?> -->
                <?php // global $withcomments; $withcomments = 1;
                //comments_template( '', true ); ?>

<?php //end of posts output

endif; $counter++;
endwhile;
rewind_posts();
echo '</div>'; //closes the column div
endfor; ?>

<?php /* Display navigation to next/previous pages when applicable */ ?>
<?php if (  $wp_query->max_num_pages > 1 ) : ?>
                                <div id="nav-below" class="navigation">
                                <?php if(function_exists('wp_pagenavi')) :
 wp_pagenavi();
else : ?>
                                        <div class="nav-previous"><?php next_posts_link( __( '<span class="meta-nav">?</span> Older posts', 'twentyten' ) ); ?></div>
                                        <div class="nav-next"><?php previous_posts_link( __( 'Newer posts <span class="meta-nav">?</span>', 'twentyten' ) ); ?></div>
                                        <?php endif; ?>
                                </div><!-- #nav-below -->

<?php endif;
 wp_reset_query(); ?>