i designed a wordpress page where i'm able to pick the groups in menu. around the category page i call

<?php get_template_part( 'loop', 'thumbnail' ); ?>

in Thumbnail i recieve all pictures and game titles from the publish and demonstrate to them.

now after i click "all" it shows me all posts. after i click "category one" it shows only posts in category one.

what i must do would be to sort the groups. after i click category one it will show me the course one posts first and then others inside a different style (e.g. black and whitened)

is the fact that possible?

this is exactly what it appears like at this time

div id="thumbwrapper">
<?php 
$i=0; //start the count at "0"
if ( have_posts() ) while ( have_posts() ) : the_post(); 
$i++; //add 1 to the total count
?>

<div id="<?php if($i===6){ echo 'thumbpost-right'; } else{echo 'thumbpost-left';} ?>" class"thumbpost">
<a href="<?php echo the_permalink() ?>">
<?php 

$thumbnail = get_post_meta($post->ID, 'thumbnail', true);

if( $thumbnail ):
echo '<img class="attachment-thumbnail" src="' .get_post_meta($post->ID, 'thumbnail', true) . '" width="125" height="90" alt="' . get_the_title() .'" /></a>';
elseif( has_post_thumbnail() ): 
the_post_thumbnail('thumbnail');

else:
echo '<img class="attachment-thumbnail" src="' . get_bloginfo('stylesheet_directory') . '/images/thumbnail-default.jpg" width="125" height="90" alt="' . get_the_title() .'" />';     
endif;

?>
<?php echo '<div id="morediv"><span class="desc">' . get_the_title() .'</span></div>'; ?>
</a>

</div><!-- .post -->
<?php
if($i===6){
$i=0;
}
?>      

<?php endwhile; // end of the loop. ?>
</div>