can't retrieve query var

I have this in functions.php:

add_filter('query_vars', 'jma_queryvars' );
function jma_queryvars( $qvars )
{
  $qvars[] = 'jmaroom';
  return $qvars;
}

and this inside the genesis_after_post hook:

$justclickedroom = 53;//default display 'post__in'
if( isset( $wp_query->query_vars['jmaroom'] )) {
	$justclickedroom = $wp_query->query_vars['jmaroom'];
}

I’m looking at this page:
http://whitestone.cleansupersites.com/rooms/
I assume that I should see jmaroom in the var dump and failing that I have no hope of success. I have tried the same filter is twenty ten with no plugins and still not gotten jmaroom in the var dump?
I am trying to use the query var to pick the post to be displayed below.
thanks,
John