How do you Slow down Post Speed Slide

I have banner image save as Post and running as Slide. It is going too fast and I am trying to slow it down. How do I do that? Below is the code save in Header.php

<div id=”banner”>
<div id=”slider”>

<?php $counter = 0; query_posts(‘category_name=homepage-banners&orderby=meta_value&meta_key=menu_order&order=asc’);
while (have_posts()) : the_post(); $counter++; ?>
<li class=”slide<?php echo $counter; ?>”><?php the_content(); ?>
<?php $bannerlink = get_post_meta($post->ID, “link”, true); if($bannerlink!=””) echo ““; ?>
<div class=”bannerbg”></div>

<?php endwhile; wp_reset_query(); ?>

</div>