<?php
    session_start();
    if(empty($pr)){
    if(isset($_GET['login']) && isset($_GET['password']) && $_GET['password'] == $_GET['confirm']){
        header("Location: index.php");
     }};
?>
<form action = "" method = "GET">
    <input name="login" placeholder="Login"></br>
    <input type="password" name="password" placeholder="Password"></br>
    <input type="password" name="confirm" placeholder="Confirm pass"></br>
    <input type="date" name="date" placeholder="Birthday"></br>
    <input type="email" name="email" placeholder="Email"></br>
    <input type="submit">
</form>
<?php
    $host = "localhost";
    $user = "root";
    $pass = "root";
    $name = "test";
    $link = mysqli_connect($host,$user,$pass,$name);

    if (!empty($_GET['login']) and !empty($_GET['password']) and $_GET['password'] == $_GET['confirm']){
        $conf = $_GET['confirm'];
        $login = $_GET['login'];
        $pass = $_GET['password'];
        $email = $_GET['email'];
        $birt = $_GET['date'];
        $today = date('Y-m-d');
        $qu = "SELECT * FROM users WHERE login='$login'";
        $res = mysqli_query($link,$qu);
        $pr = mysqli_fetch_assoc($res);
        if(empty($pr)){
            $query = "INSERT INTO users SET login='$login',password='$pass',Email='$email',birthday='$birt',today='$today'";
            $_SESSION['auto'] = true;
            mysqli_query($link,$query);
            $id = mysqli_insert_id($link);
            $_SESSION['id'] = $id;
            } else {
            echo "Логин занят";
        }
     } else {
         echo "Пароли не совпдаюат";
     }
?>