I wasn’t able to recreate the error. Maybe it’s coming from <?php get_sidebars('right'); ?>
I did change your code a little, but it didn’t give the “unexpected endwhile” error you spoke of. If it’s coming from line 1 I’d guess it’s the header.php file?
Here is the adjusted code if you want to try it:
<?php
/*
Template Name: sliderpage */
?>
<?php get_header(); ?>
<div class="span-24" id="contentwrap">
<div class="span-24" id="contentwrap">
<div class="span-14">
<?php
$myslider=new WP_query('showposts=5&cat=13');
//var_dump($myslider);
if($myslider->have_posts()):
while ($myslider->have_posts()) : $myslider->the_post();
?>
<div id="slider" class="nivoSlider">
<a href="https://wordpress.stackexchange.com/questions/51351/<?php the_permalink() ?>" class="post-image">
<img src="<?php echo $featured_image_url [0]; ?>" alt="slider-image" title="<?php the_title(); ?>" />
</a>
<?php endwhile; endif; wp_reset_query(); ?>
</div>
<div id="content"></div>
</div>
<?php get_sidebars('right'); ?>
</div>
<?php get_footer(); ?>
Your code also used <?
instead of <?php
. Short Tags aren’t supported in WordPress. Although this isn’t the cause of the error it’s good to practice proper coding standards.