Simple Post List Alternate BG

<?php
/**
 * The loop that displays just titles.
 *
 * @package WordPress
 * @subpackage Twenty_Ten
 * @since Twenty Ten 1.0
 */
?>

<?php /* Display navigation to next/previous pages when applicable */ ?>
<?php if ( $wp_query->max_num_pages > 1 ) : ?>
        <?php /* add page navigation to indexes */ ?>
        <?php if(function_exists('wp_pagenavi') ) : ?>
            <?php wp_pagenavi(); ?>
        <?php else: ?>
        <div id="nav-above" class="navigation">
            <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>
        </div>
        <?php endif; ?>
<?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 inside the list box. */ ?>

<div class="list-box">
<?php while ( have_posts() ) : the_post(); ?>

<?php $counter++; $style=""; ?>

<?php if($counter % 2) $style='style="background-color: #f5f5f5";'; ?>
<?php /* Display post list of titles */ ?>

        <div id="post-<?php the_ID(); ?>" <?php post_class(); ?> <?php echo $style; ?> >
            <h2 class="list-title">
                <a href="<?php the_permalink(); ?>" title="<?php printf( esc_attr__( 'Permalink to %s', 'twentyten' ), the_title_attribute( 'echo=0' ) ); ?>" rel="bookmark"><?php the_title(); ?></a></h2>
        </div><!-- #post-## -->

<?php endwhile; // End the loop. Whew. ?>

</div>

<?php /* Display navigation to next/previous pages when applicable */ ?>
<?php if (  $wp_query->max_num_pages > 1 ) : ?>
        <?php /* add page navigation to indexes */ ?>
        <?php if(function_exists('wp_pagenavi') ) : ?>
            <?php wp_pagenavi(); ?>
        <?php else: ?>
                <div id="nav-below" class="navigation">
                    <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>
                </div><!-- #nav-below -->
        <?php endif; ?>
<?php endif; ?>