<?php
      // create an array to hold the references
    $refs = array();

    // create and array to hold the list
    $list = array();

    $sql = "SELECT id, idparent, name, location FROM menu ORDER BY name";

    $result = $conn->query($sql);
    if ($result->num_rows > 0) {
      while ($row = $result->fetch_assoc()) {
        // Assign by reference
        $thisref = &$refs[ $row['id'] ];

        // add the the menu parent
        $thisref['idparent'] = $row['idparent'];
        $thisref['name'] = $row['name'];
        $thisref['location'] = $row['location'];

        // if there is no parent id
        if ($row['idparent'] == 0)
        {
            $list[ $row['id'] ] = &$thisref;
        }
        else
        {
            $refs[ $row['idparent'] ]['children'][ $row['id'] ] = &$thisref;
        }
      }
    } else {
      echo "0 results";
    }

    $conn->close();

    function create_menu( $arr )
    {
      $html = "\n<ul>\n";
      foreach ($arr as $key=>$val)
      {
        $html .= '<li><a href="'.$val['location'].'">'.$val['name']."</a>";
        if (array_key_exists('children', $val))
        {
            $html .= create_menu($val['children']);
        }
        $html .= "</li>\n";
      }
      $html .= "</ul>\n";
      return $html;
    }

    echo create_menu( $list );
    ?>