电子邮件验证 - 验证后登录时出现空白页

Question

我最近使用了http://tutsforweb.blogspot.co.uk/2012/05/registration-system-with-email.html的教程。我在我的用户表中添加了一个名为'com_code'的新字段，并将默认值定义为NULL。

confirm.php和registeraction.php都工作，因为当用户注册时，passkey变量被插入到数据库的com_code字段中，当他们点击电子邮件中的验证链接时，com_code字段是然后设置为NULL。

我的问题是当这个用户登录时，会出现一个空白页（其中url卡在loginaction.php处理表单的位置）。我在loginaction.php代码中出错的任何想法？我是PHP的新手，所以尽可能多的解释会很棒!!

loginaction.php

<?php require 'config/init.php';
 // Get the data collected from the user and database

$email = trim($_POST["email"]);

$password = trim($_POST["password"]);


//Check for errors

if (empty($email) or empty($password)) {

$_SESSION["message"] = "Must enter Email and Password ";

header("Location: login.php");  //Redirection information

exit ;//Ends the script

}

$email = strip_tags($email);

$password = strip_tags($password);

$pwd = $_POST["password"];

    $sql = "SELECT * FROM user WHERE email='$email' AND com_code is NULL";
    $result = mysqli_query($mysqli,$sql)or die(mysqli_error());
    if ($result->num_rows === 1) {
        $row = $result->fetch_array(MYSQLI_ASSOC);
        if (password_verify($pwd, $row['password'])) {
            $_SESSION["authenticatedUserEmail"] = $email;
            $_SESSION["unauthenticatedAdmin"] = $_SESSION['usertype'] == '0';

            //We could also use information drawn from the database eg ID

            $_SESSION['id'] = $row['id'];
            $_SESSION['first_name'] = $row['first_name'];
            $_SESSION['last_name'] = $row['last_name'];
            $_SESSION['password'] = $row['password'];
            $_SESSION['username'] = $row['username'];
            $_SESSION['usertype'] = $row['usertype'];
            $_SESSION['email'] = $row['email'];

            if ($_SESSION['usertype'] == '1') {
                header("Location: admin.php");
            } else {
                header("Location: profile.php");
            }

        }
        else {
            //Login was unsuccessful

            $_SESSION["message"] = "Could not login as $email";
            header("Location: login.php");   //Go back to the login pages
        }
}//End else
?>