Untitled

<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <title>Авторизация</title>
    <link rel="stylesheet" href="style.css">
  </head>
  <body>
   <?php
  session_start();
  $mysqli = new mysqli("domen", "login", "password", "DB");
  if(isset($_POST["send"])){


    $login = htmlspecialchars($_POST["login"]);
    $pswrd = htmlspecialchars($_POST["password"]);

    $_SESSION["login"] = $login;
    $_SESSION["pswrd"] = $pswrd;

    $error_login = "";
    $error_pswrd = "";
    $error_auth = "";

    if (strlen($login) == 0) {
      $error_login = "Введите login";
    }

    if (strlen($pswrd) == 0) {
      $error_pswrd = "Введите пароль";
    }

    if ($mysqli->query("SELECT count(`id`) FROM `users` WHERE `login`='$login' AND `password`='".md5("$pswrd")."' ") != 0) {
                header("Location: http://www.pupok.ru/Devices/show.php");
    }

        else {
             $error_auth = "Учетная запись с таким логином не существует";
        }

  }
    ?>


    <form name="feedback" action="" method="post">
      <label>Введите ваш логин</label><br>
      <input type="text" name="login" placeholder="Ваш логин" value="<?=$_SESSION["login"]?>">
      <span style="color:red"><?=$error_login?></span><br>

      <label>Введите ваш пароль</label><br>
      <input type="password" name="password" placeholder="Ваш пароль" value="<?=$_SESSION["pswrd"]?>">
      <span style="color:red"><?=$error_pswrd?></span>
      <span style="color:red"><?=$error_auth?></span><br>
      <input type="submit" name="send" value="Отправить">
    </form>
  </body>
</html>