How to fix PHP saying boxes are empty - php

Question

PHP saying theres nothing in the boxes when I put stuff in.
Tried putting var_dump($_POST); die(); at the top of register.php and it showed what I put in the boxes
Not sure what's going on here.
Any help is appreciated. Thanks in advance.
I've spent a while trying to figure this out.
Will login work aswell?
Thanks,
Jon
functions.php
<?php
session_start();
// connect to database
$db = mysqli_connect(:-));
// variable declaration
$username = "";
$email = "";
$errors = array();
// call the register() function if register_btn is clicked
if (isset($_POST['register_btn'])) {
register();
}
// REGISTER USER
function register(){
// call these variables with the global keyword to make them available in function
global $db, $errors, $username, $email;
// receive all input values from the form. Call the e() function
// defined below to escape form values
$username = e($_POST['username']);
$email = e($_POST['email']);
$password_1 = e($_POST['password_1']);
$password_2 = e($_POST['password_2']);
// form validation: ensure that the form is correctly filled
if (empty($username)) {
array_push($errors, "Username is required");
}
if (empty($email)) {
array_push($errors, "Email is required");
}
if (empty($password_1)) {
array_push($errors, "Password is required");
}
if ($password_1 != $password_2) {
array_push($errors, "The two passwords do not match");
}
// register user if there are no errors in the form
if (count($errors) == 0) {
$password = md5($password_1);//encrypt the password before saving in the database
if (isset($_POST['user_type'])) {
$user_type = e($_POST['user_type']);
$query = "INSERT INTO users (username, email, user_type, password)
VALUES('$username', '$email', '$user_type', '$password')";
mysqli_query($db, $query);
$_SESSION['success'] = "New user successfully created!!";
header('location: home.php');
}else{
$query = "INSERT INTO users (username, email, user_type, password)
VALUES('$username', '$email', 'user', '$password')";
mysqli_query($db, $query);
// get id of the created user
$logged_in_user_id = mysqli_insert_id($db);
$_SESSION['user'] = getUserById($logged_in_user_id); // put logged in user in session
$_SESSION['success'] = "You are now logged in";
header('location: index.php');
}
}
}
// return user array from their id
function getUserById($id){
global $db;
$query = "SELECT * FROM users WHERE id=" . $id;
$result = mysqli_query($db, $query);
$user = mysqli_fetch_assoc($result);
return $user;
}
// escape string
function e($val){
global $db;
return mysqli_real_escape_string($db, trim($val));
}
function display_error() {
global $errors;
if (count($errors) > 0){
echo '<div class="error">';
foreach ($errors as $error){
echo $error .'<br>';
}
echo '</div>';
}
}
function isLoggedIn()
{
if (isset($_SESSION['user'])) {
return true;
}else{
return false;
}
}
if (isset($_GET['logout'])) {
session_destroy();
unset($_SESSION['user']);
header("location: login.php");
}
if (isset($_POST['login_btn'])) {
login();
}
// LOGIN USER
function login(){
global $db, $username, $errors;
// grap form values
$username = e($_POST['username']);
$password = e($_POST['password']);
// make sure form is filled properly
if (empty($username)) {
array_push($errors, "Username is required");
}
if (empty($password)) {
array_push($errors, "Password is required");
}
// attempt login if no errors on form
if (count($errors) == 0) {
$password = md5($password);
$query = "SELECT * FROM users WHERE username='$username' AND password='$password' LIMIT 1";
$results = mysqli_query($db, $query);
if (mysqli_num_rows($results) == 1) { // user found
// check if user is admin or user
$logged_in_user = mysqli_fetch_assoc($results);
if ($logged_in_user['user_type'] == 'admin') {
$_SESSION['user'] = $logged_in_user;
$_SESSION['success'] = "You are now logged in";
header('location: admin/home.php');
}else{
$_SESSION['user'] = $logged_in_user;
$_SESSION['success'] = "You are now logged in";
header('location: index.php');
}
}else {
array_push($errors, "Wrong username/password combination");
}
}
}
// ...
function isAdmin()
{
if (isset($_SESSION['user']) && $_SESSION['user']['user_type'] == 'admin' ) {
return true;
}else{
return false;
}
}
register.php
<?php
include('functions.php');
?>
<!DOCTYPE html>
<html>
<head>
<title>Register | Vex Radio</title>
<link rel="stylesheet" href="style.css">
</head>
<body>
<div class="header">
<h2>Register</h2>
</div>
<form method="post" action="register.php">
<p><?php echo display_error(); ?></p>
<div class="input-group">
<label>Username</label>
<input type="text" name="username" value="<?php echo $username; ?>">
</div>
<div class="input-group">
<label>Email</label>
<input type="email" name="email" value="<?php echo $email; ?>">
</div>
<div class="input-group">
<label>Password</label>
<input type="password" name="password_1">
</div>
<div class="input-group">
<label>Confirm password</label>
<input type="password" name="password_2">
</div>
<div class="input-group">
<button type="submit" class="btn" name="register_btn">Register</button>
</div>
<p>
Already a member? Sign in
</p>
</form>
</body>
</html>
PHP to save the items in a DB and allow me to login