总是报错 ！

// 确定当前页数 $p 参数$p = $_GET['p']?$_GET['p']:1;// 数据指针$offset = ($p-1)*$pagesize;$query_sql = "SELECT * FROM guestbook ORDER BY id DESC LIMIT  $offset , $pagesize";$result = mysql_query($query_sql);// 如果出现错误并退出if(!$result) exit('查询数据错误：'.mysql_error());// 循环输出while($gb_array = mysql_fetch_array($result)){?><div class="guestbook-list"><p class="guestbook-head"><img  src="images/<?=$gb_array['face']? alt="总是报错 ！" >.gif" /><span class="bold"><?=$gb_array['nickname']?></span> <span class="guestbook-time">[<?=date("Y-m-d H:i", $gb_array['createtime'])?>]</span></p><p class="guestbook-content"><?=nl2br($gb_array['content'])?></p><?php	// 回复	if(!empty($gb_array['replytime'])) {?><p class="guestbook-head">管理员回复： <span class="guestbook-time">[<?=date("Y-m-d H:i", $gb_array['replytime'])?>]</span></p><p class="guestbook-content"><?=nl2br($gb_array['reply'])?></p><?php	}	// 回复结束?></div><?php}	//while循环结束?><div class="guestbook-list guestbook-page"><p><?php//计算留言页数$count_result = mysql_query("SELECT count(*) FROM guestbook");$count_array = mysql_fetch_array($count_result);$pagenum = ceil($count_array['count(*)']/$pagesize);echo '共 ',$count_array['count(*)'],' 条留言';if ($pagenum > 1) {	for($i=1;$i<=$pagenum;$i++) {		if($i==$p) {			echo ' [',$i,']';		} else {			echo ' <a href="index.php?p=',$i,'">'.$i.'</a>';		}	}}?></p></div></div><!--留言列表结束-->

数据库连接

<?php/******************************数据库连接*****************************/$conn = @mysql_connect("localhost","","");if (!$conn){	die("连接数据库失败：" . mysql_error());}mysql_select_db("guestbook", $conn);//字符转换，读库mysql_query("set character set 'gbk'");//写库mysql_query("set names 'gbk'");?>

数据库建立

CREATE TABLE `guestbook` (  `id` mediumint(8) unsigned NOT NULL auto_increment,  `nickname` char(16) NOT NULL,  `email` varchar(60) default NULL,  `face` tinyint(2) unsigned NOT NULL default '1',  `content` text NOT NULL,  `createtime` int(10) unsigned NOT NULL default '0',  `clientip` char(15) NOT NULL,  `reply` text,  `replytime` int(10) unsigned default NULL,  PRIMARY KEY  (`id`)) ENGINE=MyISAM  DEFAULT CHARSET=utf8 AUTO_INCREMENT=1 ;

但是一 测试就这句$p = $_GET['p']?$_GET['p']:1;报错 怎么办？

回复讨论(解决方案)

$_GET['p'] 是传入的变量，第一次执行就不会有，所以会报错

$p = isset($_GET['p']) ? $_GET['p'] : 1;