[Plugin: My Post Order] Search Posts doesn't work

I made a small adjustment to your code, because with the search results I got posts which are not published and got all post types, so I changed this:

add_action( 'wp_ajax_search_posts', 'mpo_search_posts' );
  function mpo_search_posts() {
    $_POST      = array_map( 'stripslashes_deep', $_POST );

    $search_str = $_POST['search_str'];
    $args = array('s' => $search_str);
    require_once ('show_posts.php');
    exit;
  }

To this:

add_action( 'wp_ajax_search_posts', 'mpo_search_posts' );
  function mpo_search_posts() {
    $_POST      = array_map( 'stripslashes_deep', $_POST );

    $search_str = $_POST['search_str'];
    $args = array('s' => $search_str, 'post_type' => 'post', 'post_status' => 'publish');
    require_once ('show_posts.php');
    exit;
  }

[Moderator Note: Please post code or markup snippets between backticks or use the code button.]

Cheers,
Jeroen

No, not when you search, then you get all results (so also pages, not published posts and other post types).