<?php

   // Create Categories, Forums and Sub-Forums
   $mysql_query = "SELECT * FROM forums WHERE forum_parent=0";
   $mysql_row = @mysqli_query ($db_connect, $mysql_query);

   //Categories
   while ($row_category = mysqli_fetch_array ($mysql_row)) {

      $category_id = $row_category['forum_id'];
      $category_name = $row_category['forum_name'];

      //Forums
      $mysql_query_forum = "SELECT * FROM forums WHERE forum_parent=$category_id";
      $mysql_row_forum = @mysqli_query ($db_connect, $mysql_query_forum);

      while ($row_forum = mysqli_fetch_array ($mysql_row_forum)) {

         $forum_id = $row_forum['forum_id'];
         $forum_name = $row_forum['forum_name'];

         //Subforums
         $mysql_query_subforum = "SELECT * FROM forums WHERE forum_parent=$forum_id";
         $mysql_row_subforum = @mysqli_query ($db_connect, $mysql_query_subforum);

         while ($row_subforum = mysqli_fetch_array ($mysql_row_subforum)) {

            $subforums[] = array(
            'forum_name' =>  $row_subforum['forum_name'],
            'forum_id' =>  $row_subforum['forum_name']
            );
         }

         $forums[] = array(
            'forum_name' => $forum_name,
            'forum_id' => $forum_id,
            'forums' => $subforums
         );

         unset($subforums);

      }

      $category[] = array(
         'forum_name' => $category_name,
         'forum_id' => $category_id,
         'forums' => $forums
      );

      unset($forums);
   }

   $forum = $category;
   $smarty->assign('forum', $forum);

?>