A password checker for PHP

secure.php

<?php

$username = "user";
$password = "password";

if ((!isset($_POST["user"])) && (!isset($_POST["pw"]))){
  echo "<form action=\"secure.php\" method=\"post\">";
  echo "username: <input type=\"text\" name=\"user\"><br />";
  echo "password: <input type=\"password\" name=\"pw\">";
  echo "<input type=\"submit\" value=\"Abschicken\">";
  echo "</form>";
}
else if ((isset($_POST["user"])) && (isset($_POST["pw"])) && ($_POST["user"] == $username) && ($_POST["pw"] == $password)){
  echo "Hier steht sicheres zeug";
}
?>