guestbook-PHP 请问 Notice: Undefined variable

guestbookphp

Notice: Undefined variable: rs in /home/sujata/Public/guestbook4/edit.php on line 44 (48,52,56)
44行：

<code> <td><input type="text" name="username" value="<?php echo $rs['username'];?>"></td></code>

请问问题出在哪里？

edit.php:

<code> <?phpdefine ('DEBUG', ture);if (DEBUG) {    ini_set("display_errors", 1);    error_reporting(E_ALL);}include "conn.php";if (!empty($_GET['id'])) {    $sql = 'SELECT * FROM user where id =  ' . $_GET['id'];    $query = mysql_query($sql);    $rs = mysql_fetch_array($query);}if (!empty($_POST['sub'])) {    $username = $_POST['username'];    $email = $_POST['email'];    $content = $_POST['content'];    $refer_url = $_POST['refer_url'];    $mysql = 'UPDATE user SET username = ' . $username . ', email = ' . $email . ', content = ' . $content . ', refer_url = ' . $refer_url;    if (mysql_query($mysql)) {        echo "修改成功！";        header("refresh:5;url = 'admin.php'");    } else {        echo "修改失败";    }}?>       <meta http-equiv="content-type" content="text/html" charset="utf8">    <title>编辑</title>        <table>      <form method="post" action="edit.php">        <tr>        <td>用户名:</td>        <td><input type="text" name="username" value="<?php echo $rs['username'];?>"></td>        </tr>        <tr>        <td>邮箱:</td>        <td>
<input type="text" name="email" value="<?php echo $rs['email'];?>">请输入你的邮箱，方便我们及时取得联系</td>        </tr>        <tr>        <td>内容:</td>        <td><textarea name="content" cols="50" rows="5"><?php echo $rs['content'];?></textarea></td>        </tr>        <tr>        <td>反馈网址:</td>        <td><input type="text" name="refer_url" value="<?php echo $rs['refer_url'];?>"></td>        </tr>        <tr>        <td><input type="submit" name="sub" value="提交"></td>        </tr>      </form>    </table>   </code>

admin.php:

<code> <h1>管理员后台</h1>
<?phpinclude "conn.php";$sql = "select * from user";$query = mysql_query($sql);while ($rs = mysql_fetch_array($query)) {    ?>       <meta http-equiv="content-type" content="text/html" charset="utf8">    <title>管理员后台</title>      <hr>    <table>      <form method="post" action="index.php">        <tr>        <td>用户名:</td>        <td>
<?php echo $rs['username'];?>  <a href="edit.php?id=<?php%20echo%20%24rs%5B'id'%5D?>">编辑</a>   <a href="del.php?del=<?php%20echo%20%24rs%5B'id'%5D?>">删除</a>
</td>        </tr>        <tr>        <td>留言时间:</td>        <td><?php echo $rs['dates'];?></td>        </tr>        <tr>        <td>邮件:</td>        <td><?php echo $rs['email'];?></td>        </tr>        <tr>        <td>内容:</td>        <td><?php echo $rs['content'];?></td>        </tr>        <tr>        <td>反馈网址:</td>        <td><?php echo $rs['refer_url'];?></td>        </tr>      </form>    </table>    <?php }?></code>

index.php:

<code>include "conn.php"; //连接数据库文件if (!empty($_POST['sub'])) {    $username = $_POST['username'];    $email = $_POST['email'];    $content = $_POST['content'];    $refer_url = $_POST['refer_url'];    $sql = "insert into `user` (`id`,`username`,`dates`,`email`,`content`,`refer_url`) VALUES (null,'$username',now(),'$email','$content','$refer_url')";    $query = mysql_query($sql);    if ($query) {        echo ("已经收到你的信息啦，我们会加快步伐改进的。谢谢你的建议！<br>");        echo ("<a href="#">5秒后将自动跳转到首页，如果没有跳转你可以直接点击此连接</a>");        header("refresh:5;url='index.php'");    } else {        echo "对不起，忙碌....能重新再试一遍吗？>_       <meta http-equiv="content-type" content="text/html" charset="utf8">    <title>意见反馈</title>        <table>      <form method="post" action="index.php">        <tr>          <td>用户名:</td>          <td><input type="text" name="username" value=""></td>        </tr>        <tr>          <td>邮箱:</td>          <td>
<input type="text" name="email" value="">请输入你的邮箱，方便我们及时取得联系</td>        </tr>        <tr>          <td>内容:</td>          <td><textarea name="content" cols="50" rows="5">说点什么？</textarea></td>        </tr>        <tr>          <td>反馈网址:</td>          <td><input type="text" name="refer_url" value=""></td>        </tr>        <tr>         <td><input type="submit" name="sub" value="提交"></td>        </tr>      </form>    </table>   </code>