PHP problem

// yo if anyone on pastebin is reading this who can help please add me on discord and i'll love you forever
// Just!n#3957

<?php
  include './../config.php';
echo '<form action="" method="POST">User: <input type="text" name="user" /><br />Pass: <input type="password" name="pwd" /><input type="submit" name="submit" style="display:none;"/></form>';
        if(isset($_POST['submit'])){
            $user = md5($_POST['user']);
            $pwd = md5($_POST['pwd']);}
            if($user == "$username" && $pwd == "$password"){
                echo " ";
                exit;
            }

            else{
                if($user == "NULL" && $pwd == "NULL"){
                echo "Password incorrect";
                exit;
            }}

?>


<title id="pageTitle">logs</title>
<other stuff down here>