Till Sakke

<?php

/*

1. User clicks HTML-form submit button

1.1. Error handler 1 - Checks for empty fields and cancels submission if empty fields are detected.

2. Switch statement to give suiting error messages based on results from error handlers.

*/

if (isset($_POST['submitButton'])) {

    // Requires dbh-file for connection to MySQLi-database

    require 'dbh.inc.php';

    // PHP-variables for input fields (3)

    $username = $_POST['username'];
    $password = $_POST['password'];
    $rePassword = $_POST['rePassword'];

    // Error handler 1

    if (empty($username) || empty($password) || empty($rePassword)) {
        header('Location: signup.php?error=empty_inputs');
        die();
    }

    // Switch statement for generating error messages

    if (isset($_GET['error'])) {

        switch($_GET['error']) {

            case 'empty_inputs':
            echo 'Please fill in all fields to proceed.';
            break;

            default:
            echo 'Unknown error.';
            break;

        }

    }

}