<?php require_once 'db.php'
$display_name = $_POST["dispaly-name"]; $email = $_POST['email']; $password = $_POST['password']; $password_conf = $_POST['password_conf']
$register = mysqli_query($db, "INSERT INTO users (display_name, email, password) VALUES ('$display_name', '$email', '$password')"); if($register){ echo 'done'; }else{ echo 'error'; } ?>