I need some help to solve this problem. I currently have a website with a database attached with myphpadmin/sql.
I have a register site that redirects users to this url when the registration fields are empty. (http://localhost/register.php?signup=empty)
the problem i am have is that when i try to login on my login page, i want the user to be redirected to this these two url's when an error or empty fields occures. (index.php?login=empty) and (index.php?login=error). and then (index.php?login=success) when the correct credentials have been typed.
The problem is that when i submit the login on my login/index page, i always gets redirected to (index.php?login=empty).
Therefore i think that my fields on the login page are linked to something that aint right?? But i really cant seeem to solve the problem. So any help would be appreciated.
This is my code.
INDEX.php
    <?php
    session_start();
    ?>
    <!DOCTYPE html <html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
        <link rel="stylesheet" type="text/css" href="stylesheet.css" />
        <title>CSS Login form</title>
    </head>
    <body>
        <div class="login">
            <form class=”loginform” action="login.php" method="POST">
                <label for="name" style="color: blue;">name</label>
                <br>
                <input type="text" name="name" id="name" />
                <br>
                <label for="password">password</label>
                <br>
                <input type="password" name="password" id="password" />
                <br>
                <button type="submit" name="submit">Sign in</button>
    <!--             <input type="submit" name="submit" value="Sign In"> </form> -->
            <input type="button" value="Sign Up" onclick="location.href='register.php';" />
            </form>
        </div>
    </body>
    </html>
    LOGIN.php
    <?php
    session_start();
    if (isset($_POST['submit'])) {
        include 'dbh.inc.php';
        $name = mysqli_real_escape_string($conn, $_POST['name']);
        $password = mysqli_real_escape_string($conn, $_POST['password']);
        //check inputs
        if (empty($name) || empty($password)) {
            header("Location: ../login.php?login=empty");
            exit();
        } else {
            $sql = "SELECT * FROM users WHERE user_name='$name'";
            $result = mysqli_query($conn, $sql);
            $resultCheck = mysqli_num_rows($result);
            if ($resulstCheck < 1) {
                header("Location: ../index.php?login=error");
                exit();
            } else {
                if ($row = mysqli_fetch_assoc($result)) {
                    //de-hashing password
                    $hashedPasswordCheck = password_verify($password, $row['user_password']);
                    if ($hashedPasswordCheck == false) {
                        header("Location: ../index.php?login=error");
                        exit();
                    } elseif ($hashedPasswordCheck == true) {
                        //If true log the user in
                        $_SESSION['u_id'] = $row['user_id'];
                        $_SESSION['u_name'] = $row['user_name'];
                        $_SESSION['u_phone'] = $row['user_phone'];
                        $_SESSION['u_email'] = $row['user_email'];
                        $_SESSION['u_zip'] = $row['user_zip'];
                        header("Location: ../index.php?login=success");
                        exit();
                    }
                }
            }
        }
    } else {
        header("Location: ../index.php?login=error");
        exit();
    }
    Register.php
    <?php
    session_start();
    //Check if the user clicked the button, 
    //to make sure they dont have acces to the code
    if (isset($_POST['submit'])) {
        include_once 'dbh.inc.php';
        $dbServername = "localhost";
        $dbUsername = "root";
        $dbPassword = "";
        $dbName = "loginsystem";
        $conn = mysqli_connect($dbServername, $dbUsername, $dbPassword, $dbName);
        $name = mysqli_real_escape_string($conn, $_POST['name']);
        $phone = mysqli_real_escape_string($conn, $_POST['phone']);
        $email = mysqli_real_escape_string($conn, $_POST['email']);
        $zip = mysqli_real_escape_string($conn, $_POST['zip']);
        $password = mysqli_real_escape_string($conn, $_POST['password']);
        if (empty($name) || empty($phone) || empty($email) || empty($zip) || empty($password)) {
            header("Location: ../register.php?signup=empty");
            exit();
        } else {
            if (
                !preg_match("/[\w\s]+/", $name) || !preg_match("/^(\\+)[0-9]{8,30}$/", $phone) ||
                !preg_match("/[^@]+@[^@]+\.[^@]+/", $email) || !preg_match("/^[0-9]{4}$/", $zip) ||
                !preg_match("/^(?=.*?[A-Z])(?=.*?[a-z])(?=.*?[0-9]).{8,}$/", $password)
            ) {
                header("Location: ../register.php?signup=invalid");
                exit();
            } else {
                //Check email
                if (!filter_var($email, FILTER_VALIDATE_EMAIL)) {
                    header("Location: ../signup.php?signup=email");
                    exit();
                } else {
                    $sql = "SELECT * FROM users WHERE user_id='$user_id'";
                    $result = mysqli_query($conn, $sql);
                    $resultCheck = mysqli_num_rows($result);
                    if ($resultCheck > 0) {
                        header("Location: ../signup.php?signup=usertaken");
                        exit();
                    } else {
                        //Hashing of the Password
                        $hashedPwd = password_hash($password, PASSWORD_DEFAULT);
                        //Insert user to database
                        $sql = "INSERT INTO users (user_name, user_phone, user_email, 
                    user_zip, user_password) VALUES ('$name', '$phone', '$email',
                    '$zip', '$hashedPwd');";
                        mysqli_query($conn, $sql);
                        header("Location: ../signup.php?signup=success");
                        exit();
                    }
                }
            }
        }
    }
    ?>
    <!DOCTYPE HTML>
    <html>
    <head></head>
    <body>
        <form class=”this.html” method="POST">
            <label for="name" style="color: blue;">name</label>
            <br>
            <input type="text" name="name" id="name" />
            <br>
            <label for="password">password</label>
            <br>
            <input type="password" name="password" id="password" />
            <br>
            <label for="phone">phone number</label>
            <br>
            <input type="text" name="phone" id="phone" />
            <br>
            <label for="email">email adress</label>
            <br>
            <input type="text" name="email" id="email" />
            <br>
            <label for="zip">zip code</label>
            <br>
            <input type="text" name="zip" id="zip" />
            <br>
            <button type="submit" name="submit">Sign up</button>
        </form>
    </body>
    </html> 
 
    