(上級) PHP+Mysql+jQuery によるパスワードの取得

<p><strong>输入您注册的电子邮箱，找回密码：</strong></p> 
<p><input type="text" class="input" name="email" id="email"><span id="chkmsg"></span></p> 
<p><input type="button" class="btn" id="sub_btn" value="提 交"></p>

$(function(){ 
    $("#sub_btn").click(function(){ 
        var email = $("#email").val(); 
        var preg = /^\w+([-+.]\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*/; //匹配Email 
        if(email=='' || !preg.test(email)){ 
            $("#chkmsg").html("请填写正确的邮箱！"); 
        }else{ 
            $("#sub_btn").attr("disabled","disabled").val('提交中..').css("cursor","default"); 
            $.post("sendmail.php",{mail:email},function(msg){ 
                if(msg=="noreg"){ 
                    $("#chkmsg").html("该邮箱尚未注册！"); 
                    $("#sub_btn").removeAttr("disabled").val('提 交').css("cursor","pointer"); 
                }else{ 
                    $(".demo").html("<h3>"+msg+"</h3>"); 
                } 
            }); 
        } 
    }); 
})

include_once("connect.php");//连接数据库 
 
$email = stripslashes(trim($_POST['mail'])); 
     
$sql = "select id,username,password from `t_user` where `email`='$email'"; 
$query = mysql_query($sql); 
$num = mysql_num_rows($query); 
if($num==0){//该邮箱尚未注册！ 
    echo 'noreg'; 
    exit;     
}else{ 
    $row = mysql_fetch_array($query); 
    $getpasstime = time(); 
    $uid = $row['id']; 
    $token = md5($uid.$row['username'].$row['password']);//组合验证码 
    $url = "http://www.helloweba.com/demo/resetpass/reset.php?email=".$email." 
&token=".$token;//构造URL 
    $time = date('Y-m-d H:i'); 
    $result = sendmail($time,$email,$url); 
    if($result==1){//邮件发送成功 
        $msg = &#39;系统已向您的邮箱发送了一封邮件<br/>请登录到您的邮箱及时重置您的密码！&#39;; 
        //更新数据发送时间 
        mysql_query("update `t_user` set `getpasstime`=&#39;$getpasstime&#39; where id=&#39;$uid &#39;"); 
    }else{ 
        $msg = $result; 
    } 
    echo $msg; 
} 
 
//发送邮件 
function sendmail($time,$email,$url){ 
    include_once("smtp.class.php"); 
    $smtpserver = ""; //SMTP服务器，如smtp.163.com 
    $smtpserverport = 25; //SMTP服务器端口 
    $smtpusermail = ""; //SMTP服务器的用户邮箱 
    $smtpuser = ""; //SMTP服务器的用户帐号 
    $smtppass = ""; //SMTP服务器的用户密码 
    $smtp = new Smtp($smtpserver, $smtpserverport, true, $smtpuser, $smtppass);  
    //这里面的一个true是表示使用身份验证,否则不使用身份验证. 
    $emailtype = "HTML"; //信件类型，文本:text；网页：HTML 
    $smtpemailto = $email; 
    $smtpemailfrom = $smtpusermail; 
    $emailsubject = "Helloweba.com - 找回密码"; 
    $emailbody = "亲爱的".$email."：<br/>您在".$time."提交了找回密码请求。请点击下面的链接重置密码 
（按钮24小时内有效）。<br/><a href=&#39;".$url."&#39;target=&#39;_blank&#39;>".$url."</a>"; 
    $rs = $smtp->sendmail($smtpemailto, $smtpemailfrom, $emailsubject, $emailbody, $emailtype); 
 
    return $rs; 
}

include_once("connect.php");//连接数据库 
 
$token = stripslashes(trim($_GET['token'])); 
$email = stripslashes(trim($_GET['email'])); 
$sql = "select * from `t_user` where email='$email'"; 
 
$query = mysql_query($sql); 
$row = mysql_fetch_array($query); 
if($row){ 
    $mt = md5($row['id'].$row['username'].$row['password']); 
    if($mt==$token){ 
        if(time()-$row['getpasstime']>24*60*60){ 
            $msg = '该链接已过期！'; 
        }else{ 
            //重置密码... 
            $msg = &#39;请重新设置密码，显示重置密码表单，<br/>这里只是演示，略过。&#39;; 
        } 
    }else{ 
        $msg =  &#39;无效的链接&#39;; 
    } 
}else{ 
    $msg =  &#39;错误的链接！&#39;;     
} 
echo $msg;

CREATE TABLE `t_user` ( 
  `id` int(11) NOT NULL auto_increment, 
  `username` varchar(30) NOT NULL, 
  `password` varchar(32) NOT NULL, 
  `email` varchar(50) NOT NULL, 
  `getpasstime` int(10) NOT NULL, 
  PRIMARY KEY  (`id`) 
) ENGINE=MyISAM  DEFAULT CHARSET=utf8;