Auto-creation of threads?

[Gryphon]

This thread has been very helpful, though I am having some trouble. Here is the my current code:

PHP Code:

if ($_POST["action"] == 'add') {
  query("INSERT INTO psu_news SET author='$user[name]', title='$_POST[title]', date_added='$setting[time]', post_id='$_POST[post_id]'");
  $psu_news_id = mysql_insert_id();

  if ($_POST["create_post"] == '1' && $_POST["post_id"] == '0') {
    // vb functions
    chdir('/home/psuwww/wwwroot/site.com/forums');
    require('./global.php');
    require('./includes/functions_newpost.php');

    $userid = 5; // The user creating the thread
    $forumid = 2; // The forum where the thread is to be posted

    // forum & user info
    $foruminfo = fetch_foruminfo($forumid);
    $bbuserinfo = fetch_userinfo($userid);

    // setup the thread
    $post[title] = '[News] '.$_POST["title"].'';
    $post[message] = '[url=http://www.site.com/index.php?newsid='.$psu_news_id.']http://www.site.com/index.php?newsid='.$psu_news_id.'[/url]';
    $post[poststarttime] = TIMENOW;
    $post[posthash] = md5($post[poststarttime] . $bbuserinfo['userid'] . $bbuserinfo['salt']);
    $post[emailupdate] = 9999;

    // build the thread
    build_new_post('thread', $foruminfo, array(), 0, $post, $errors);

    // bome back to working dir
    chdir('/home/psuwww/wwwroot/site.com/admin');
    query("UPDATE psu_news SET post_id='$post[threadid]' WHERE id='$psu_news_id'");
  }
  echo '<hr><font size="3"><b>Post Added '.$psu_news_id.'</b><hr>';
} 


The Thread title posts correctly and the Message also posts, however, $psu_news_id becomes unset. The message url in the created thread is missing the $psu_news_id and the final echo is blank.

Also, this is all done mid template on our site, and all the variables pre-defined at the top of the script are unset after this.

Any info appreciated.