层叠菜单的动态生成_PHP

  if (isset($hierarchy)){
      //$hierarchy[] = $selection;
      if (isset($hierarchy)){
        while(list($level, $sel) = each($hierarchy)){
          echo "";
          echo $level, ': ', $sel, "
n";
          $nextlevel = (int) $level + 1;
        }
    }
  }
  else{
      $nextlevel = 0;
  }
  echo "n";
  for ($I = 1; $I     echo "$In";
  }
  echo "n";
?>