删除留言总体上比较简单，就是从数据库中删除相应的数据然后回到主页就好了。
<?php
require_once("sys_conf.inc");
//连接数据库
$link_id=mysql_connect($DBHOST,$DBUSER,$DBPWD);
mysql_select_db($DBNAME); //选择数据库my_chat
//删除留言数据
$str="delete from guestbook ";
$str=$str."where rid=".$_GET["recordid"];
//echo $str;
$result=mysql_query($str,$link_id); //执行查询
//删除回复数据
$str="delete from reply ";
$str=$str."where bookidid=".$_GET["recordid"];
//echo $str;
$result=mysql_query($str,$link_id); //执行查询
mysql_close($link_id);
//返回search.php页面
echo "<script language='javascript'>";
echo " location='booklist.php?keyword=&search=1'";
echo "</script>";
?>更新留言的话涉及到取主键的问题，但和插入留言还是有太多相似的地方呢。
<!--update.php:修改留言信息--------------->
<?php
//修改完毕后，返回guest页面
if(!isset($_GET["recordid"]) or $_GET["recordid"]=="")
{
echo "<script language='javascript'>";
echo " location='booklist.php?keyword=&search=1'";
echo "</script>";
}
else {
require_once("sys_conf.inc");
//初始化页面表单中的值
//连接数据库
$link_id = mysql_connect($DBHOST, $DBUSER, $DBPWD);
mysql_select_db($DBNAME); //选择数据库my_chat
$str = "select name,homepage,location,email,message,content from guestbook where rid=" . $_GET["recordid"];
//echo $str;
$result = mysql_query($str, $link_id);
list($name2, $homepage2, $location2, $email2, $message2, $content2) = mysql_fetch_row($result);
//判断姓名和留言信息是否为空
$errorm = "";
if (isset($_POST['name']) or isset($_POST['message'])) {
// if (!isset($message) or $message=="" or !isset($name) or $name=="")
if ($_POST['name'] == "" or $_POST['message'] == "") {
$errorm = "<font color=red>出错了!!!</font>姓名和留言内容必填";
} else {
//获取并处理用户提交信息
$space = " ";
$time = date("Y年m月d日H小时i分");
$ip = $_SERVER['REMOTE_ADDR'];
$message = $_POST['message'];
$name = $_POST['name'];
$homepage = $_POST['homepage'];
$email = $_POST['email'];
$location = $_POST['location'];
$recordid=$_POST['recordid'];
$message = StripSlashes($message); //给字符串中按照需要加上""和去掉""，对于某些数据库，必须在要查询的字符加上和去掉""之后才能够查询.
$message = htmlspecialchars($message); //将HTML特殊字符换成它们的名字,例如"<"变成"<".
$message = nl2br($message); //在HTML中的每一个回车前面加上"<BR>".
$guestcontent = "<tr><td><font color=#AB00E1>留言内容:</font><br><!--content>$message<!--endcontent> ";
$guestcontent = $guestcontent . "<br><font color=#6633FF>留言人大名: </font><!--name>$name<!--endname> ";
if ($email != "") {
$guestcontent = $guestcontent . "<br><font color=#9900CC>电子信箱:</font><a href="mailto:$email"><!--email>$email<!--endemail></a>" . "$space";
}
if ($homepage != "http://") {
$guestcontent = $guestcontent . "<font color=#9900CC>主页:</font>$homepage<a href="$homepage"><!--homepage>$homepage<!--endhomepage></a>";
}
if ($location != "")
$guestcontent = $guestcontent . "<br><font color=#0000FF>时间:$time 来自:$location $ip</font>";
$guestcontent = ereg_replace(chr(10), "", $guestcontent);
$guestcontent = $guestcontent . "<hr size=1></td></tr>
";
//修改数据库
$str = "update guestbook set";
$str = $str . "time='$time',ip='$ip',name='$name',homepage='$homepage',";
$str = $str . "location='$location',email='$email',content='$guestcontent')";
$str = $str . "where rid=$recordid";
echo $str;
$result = mysql_query($str, $link_id); //执行查询
mysql_close($link_id);
}
}
}
?>
<html>
<style type=text/css>
Td {FONT-SIZE: 10pt;}
TEXTAREA
{
FONT-FAMILY: "宋体";
FONT-SIZE: 10pt;
}
</style>
<head>
<title>修改留言</title>
</head>
<body bgcolor=#FFFFFD>
<?php include "head.html"?>
<div align="center">
<table width="68%" border="1" cellpadding="3" cellspacing="0" bordercolor="#E3E3E3">
<form method="POST" action="update.php">
<?
//如果输入的用户名或留言信息为空，则报错
if ($errorm)
{
echo "<tr>";
echo "<td colspan=3 height=32> ";
echo "$errorm";
echo "</td>";
echo "<tr>";
}
?>
<tr>
<td width="22%" bgcolor="#F0F0F0"><font color="#000000">姓名<font color="#FF0033">(必填)</font></font></td>
<td colspan="2" width="78%" bgcolor="#F0F0F0"><font color="#00FF00">
<input type="text" name="name" value="<?php echo "$name2"?>" size="40">
</font></td>
</tr>
<tr>
<td width="22%" height="29">主页:</td>
<td colspan="2" height="29" width="78%">
<input type="text" name="homepage" value="<?php echo "$homepage2"?>"size="40">
</td>
</tr>
<tr>
<td width="22%" height="27" bgcolor="#F0F0F0">来自:</td>
<td colspan="2" height="27" width="78%" bgcolor="#F0F0F0">
<input type="text" name="location" value="<?php echo "$location2"?>" size="40">
</td>
</tr>
<tr>
<td width="22%" height="20">Email:</td>
<td colspan="2" height="20" width="78%"><font color="#00FF00">
<input type="text" name="email" value="<?php echo $email2 ?>" size="40">
</font></td>
</tr>
<tr>
<td colspan="3" valign="middle" align="left">
<div align="center"><font color="#000000">请留言</font><font color="#FF0033">(必填)</font><font color="#00FF00"><br>
<textarea rows="6" name="message" cols="55" wrap="VIRTUAL"><?php echo $message2 ?></textarea>
<!-- 自动换行用wrap-->
</font></div>
</td>
</tr>
<tr bgcolor="#F0F0F0">
<td colspan="3" height="24">
<div align="center"><font color="#00FF00">
<input type=hidden value=<?php if(isset($_GET["recordid"])) echo $_GET["recordid"];?> name=recordid>
<input type="submit" value="提 交" name="B1">
<input type="reset" value="重 写" name="B2">
</font></div>
</td>
</tr>
</form>
</table>
</body>
</html>