Post query missing an elseif statement

The else in PHP goes at the end of the if statements closing bracket, look at the following:

if( 1 == 1 ) {
    echo 'true!';
}
else {
    echo 'false.';
}

So you code would look something like this:

<?php 
    $posts = get_posts(array(
        'post_type' => 'retail_units',
        'orderby' => 'date',
        'order' => 'ASC'
        ));

    if( ! empty( $posts ) ) { 
        foreach( $posts as $post ) { setup_postdata( $post ); 
?>

    <li>
        <a href="https://wordpress.stackexchange.com/questions/168269/<?php the_permalink();?>"><?php the_title(); ?></a>
    </li>
    <div style="clear:both;"></div>
<?php 
    }
    wp_reset_postdata(); 
    } else { 
?>
    <li>No Posts Found.</li>
<?php } ?>