Continious next & previous on single.php

Please can someone advise if it is possible to have continious next previous links on my single.php page. Please see my code so far below…

<div id="rightgall">
<div class="pagenav">
<?php previous_post_link('%link', '<img src="previous.jpg" width="12" height="121" alt="previous" />', TRUE); ?>
            <?php
$prevPost = get_previous_post();
$prevthumbnail = get_the_post_thumbnail($prevPost->ID, array(100,100) );
previous_post_link('%link',''.$prevthumbnail.'', TRUE);
?></div>
<div class="pagenav">
<?php
$nextPost = get_next_post();
$nextthumbnail = get_the_post_thumbnail($nextPost->ID, array(100,100) );
next_post_link('%link',''.$nextthumbnail.'', TRUE);
?>
<?php next_post_link('%link', '<img src="next.jpg" width="15" height="121" alt="next" />', TRUE); ?>

</div></div>