Assistance with Loop and PHP

I’m using this loop in an attempt to get three posts that have images. I believe the issue has something to do with the way I’m incrementing $varz or the way the While statement is setup. Using this code currently returns a blank page with no content. Any help is much appreciated.

<div class="featured-sidebar first">
    <?php $varz = 1 ?>
    <?php query_posts( 'cat=32,45,46,43,44,104,23,31,36&posts_per_page=20') ?>
    <?php if ( have_posts() ) : while ( $varz < 4 ) : the_post(); ?>
        <?php if ( has_post_thumbnail() ) {?>
            <?php if ($varz = 1){
                        echo"<img class=\"most-pop-overlay1\" src=";print IMAGES;echo"/images/one-overlay.png\" />"; }
                  elseif ($varz = 2){
                        echo"<img class=\"most-pop-overlay2\" src=";print IMAGES;echo"/images/two-overlay.png\" />"; }
                  elseif ($varz = 3){
                        echo"<img class=\"most-pop-overlay3\" src=";print IMAGES;echo"/images/three-overlay.png\" />"; }
                  else{}
            ?>
            <?php $url = wp_get_attachment_url( get_post_thumbnail_id($post->ID) ); ?>
                <a href="<?php the_permalink() ?>"><?php the_post_thumbnail(array(150,150)); ?></a>
                <h2><a href="<?php the_permalink() ?>"><?php the_title() ?></a></h2>
                <p>
                    <?php $exc = strip_tags(get_the_excerpt()); ?>
                    <?php echo string_limit_words($exc,12); ?>...
                </p>
            <?php $varz++; ?>
        <?php } ?>
    <?php endwhile; ?>
    <?php endif; ?>
    <?php wp_reset_query() ?>
</div>