profile.php

<?php
include("/Users/Donovan/Sites/sn/classes/DB.php");
include("/Users/Donovan/Sites/sn/classes/Login.php");

$username = "";
if (isset($_GET['username'])) {
        if (DB::query('SELECT username FROM users WHERE username=:username', array(':username'=>$_GET['username']))) {
                $username = DB::query('SELECT username FROM users WHERE username=:username', array(':username'=>$_GET['username']))[0]['username'];
                if (isset($_POST['follow'])) {
                        $userid = DB::query('SELECT id FROM users WHERE username=:username', array(':username'=>$_GET['username']))[0]['id'];
                        $followerid = Login::isLoggedIn();
                        if (!DB::query('SELECT follower_id FROM followers WHERE user_id=:userid', array(':userid'=>$userid))) {
                                DB::query('INSERT INTO followers VALUES (NULL, :userid, :followerid)', array(':userid'=>$userid, ':followerid'=>$followerid));
                        } else {
                                echo 'Already following!';
                        }
                }
        } else {
                die('User not found!');
        }
}
?>
<h1><?php echo $username; ?>'s Profile</h1>
<form action="profile.php?username=<?php echo $username; ?>" method="post">
        <input type="submit" name="follow" value="Follow">
</form>