login.php

<?php
include 'connect.php';

if(isset($_GET['redirectedFromRegister'])==1) {
    echo 'Thank you for registering, you may now login';
} else {
    echo '<h1>LOGIN</h1>';
}
?>

<html>
    <body>
        <form action="index.php" method="post">

            Username: <input type="text" name="username"/><br/>
            Password: <input type="password" name="password"/><br/>

            <input type="submit" value="LOGIN"/>
        </form>
    </body>
</html>