PHP论坛不向数据库写入数据

我显示的代码似乎在$tid=mss时停止工作
这就是为什么我认为一开始称为mss的函数不起作用的原因
当脚本在我的网站上运行时，它表现得像什么都没发生过一样，并回到你正在查看的主题。对不起，我不知道发生了什么事，所以我无话可说。如果您需要任何问题，请对此发表评论

Reply.php

  <?php
    require('connect.php');
    function mss($value) {
        return mysqli_real_escape_string(trim(strip_tags($connect, $value)));
    }
if(!$_POST['submit']) {
    echo "Invalid usage of the file!  Hmm, maybe you should try sql injection.";
} else {
    $tid = mss ($_GET['id']);
    $msg = mss ($_POST['reply']);
    if(!$tid) {
        echo "Hmm, I dont know how that you would reply to no topic but still expect it to work.";
    } else {
        $sql = "SELECT * FROM forum_topics WHERE id='".$tid."'";
        $res = mysqli_query($connect, $sql) or die (mysqli_error());
        if(mysqli_num_rows($res) == 0) {
            echo "Wat r u doin m7, you tryin to rply to a topic that doesn't exist.";
        } else {
            $row = mysqli_fetch_assoc($res);
            if(!$msg) {
                echo "You did not give a reply.";
            } else {
                if(strlen($msg) < 5 || strlen($msg) > 10000) {
                    echo "<font color='red'>Your reply must be between 5 and 10000 characters!</font>";
                } else {
                    $date = date("m-d-y") . " at " . date("h:i:s");
                    $time = time();
                    $sql3 = "INSERT INTO forum_replies (id, tid, uid, message, date, time) VALUES (default, '".$tid."','".$_SESSION['uid']."', '".$msg."', '".$date."', '".$time."')";
                    $res3 = mysqli_query($connect, $sql3) or die (mysqli_error());
                    header("Location: topics.php?id='.$tid'");
                }
            }
        }
    }
}
?>

编辑：更新代码

Connect.php

<?php
    $host="localhost";//hostname
    $username="********";//username
    $password="********";//database password
    $db_name="forum";//database name
    $connect = mysqli_connect($host, $username, $password, $db_name) or die ("<font color='red'>Unable to connect to MySQL!  Contact an admin.</font>");
?>