<?php
if ((!isset($_POST['Login_name'])) or (!isset($_POST['Password'])) or (!isset($_POST['First_name'])) or (!isset($_POST['Last_name'])) or (!isset($_POST['Email']))) {
header("Location: login page.html");
exit;
}
$mysqli = mysqli_connect("localhost", "root", "gotenks", "bpa_site");
$sql =...