一个很傻的无限分类

<?
/**
* 无限分类
* 2011/8/23
* kcj
* */
include "../conn/conn.php";
$flpid=$_POST['flpid'];
$fltitle=$_POST['title'];
$fldes=$_POST['des'];
if(isset($_POST['action'])!=''&&$_POST['action']="add"){
    $sql="insert into fenlei (flpid,fltitle,fldes) value('".$flpid."','".$fltitle."','".$fldes."')";
    mysql_query($sql);

}

?>

<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
        <title>无标题文档</title>
        <meta name="Author" content="kcj" />
        <meta name="Keywords" content="php,lampbrother" />
        <link rel="stylesheet" type="text/css" href="style/lampcms.css">
        <script src="javascript/common.js"></script>
        <script type="text/javascript">
           function vaFl(addfl){
             if(addfl.title.value==''){
                alert("栏目名称不能为空！");
                addfl.title.focus();
                return false;
             }
             if(addfl.des.value==''){
                alert("栏目描述不能为空！");
                addfl.des.focus();
                return false;
             }
           }

        </script>

    </head>
    <body>
        <div id="main">
              后台管理->添加分类
            <form method="post" action="" name="addfl" onsubmit="return vaFl(this)">
            <div class="msg-box">
                <ul class="viewmess">
                    <li class="light-row">
                        <span class="col_width">上级栏目</span>
                          <select name="flpid">
                     <option value="0">请选择分类</option>
                           <?php
    $sql="SELECT*FROM fenlei where flpid=0";                   //一个很傻的无限分类
    $rs=mysql_query($sql);
    while ($row=mysql_fetch_array($rs)) { var_dump($row);
      echo "<option value=\"$row[flid]\">$row[fltitle]</option>";

      $sql="select*from fenlei where flpid=$row[flid]";
        $rs_son=mysql_query($sql);
        while($row_son=mysql_fetch_array($rs_son)){
        echo "<option value=\"$row_son[flid]\">   $row_son[fltitle]</option>";
      }

    }
    ?>
                          </select>
                    </li>
                    <li class="dark-row">
                        <span class="col_width">栏目名称<span class="red_font">*</span></span>
                        <input type="text" class="text-box" name="title" maxlength="30" size="20" >
                    </li>
                    <li class="light-row">
                        <span class="col_width" style="margin-top:30px">栏目描述</span>
                        <textarea class="text-box" name="des" cols="30" rows="5"></textarea>

补充：Web开发 , php ,