Blog Sections - Filter by Categories

Hello,

I am trying to out put a list of blog posts from within a section.

The idea is to only show/list the blog posts that are from within a specific section that fall under a category name. At the moment it either shows all posts from within a category and seems to ignore the section.

help appreciated.

 <?php

                $posts_per_page = 10;
                $template       = 'post_in_list.html';
                $sort_order     = 'DESC';
                $sort_by        = 'postDateTime';



                if (perch_get('cat')) {
                    echo '<h1>Archive of: '.perch_blog_category(perch_get('cat'), true).'</h1>';

                    perch_blog_categories(array(
                            'category'   => perch_get('cat'),
                            'section'   => perch_get('s'),
                            'template'   => $template,
                            'count'      => $posts_per_page,
                            'sort'       => $sort_by,
                            'sort-order' => $sort_order,
                            ));

                    $posts_displayed = true;
                }



            ?>