php无限极分类问题

代码好像不能用图片贴出来晕

  输出主目录
                     <?php
                         $result=$db->query("select id,title from newscata where fid=0");
                         while($rs=$db->fetch_array($result)){
                           $rs_v[$rs['id']]=$rs['title'];
                         }
                        
                         foreach($rs_v as $key=>$val){
                           echo "&nbsp;&nbsp;<a href='?cataid=$key'>".$val."</a><br>";
                           tree($key);
                         }
                         unset($rs_v);
                      ?>

输出子目录并递归调用
function tree($sid){
  global $db;
  $results=$db->query("select id,title,level from newscata where fid=$sid");
  while($row=$db->fetch_array($results)){
    $str="&nbsp;&nbsp;";
    for($i=0; $i<=$row['level']-1; $i++){
      $str=$str."→";
    }
     echo $str."<a href='?cataid=".$row['id']."'>".$row['title']."</a><br>";
  }
  unset($row);
  unset($str);
}

正常输出

我这里有用BORPHP框架写的无限级分类。。加群：11077422