function authenticate() {

		try {
			$db = new PDO('mysql:host=localhost;dbname=users_db;charset=UTF-8', 'root', 'aiden223', array(PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION));
		} catch(PDOException $ex) {
			echo '<font face="Verdana" size="2">An error occured: ' . $ex;
		}

		$username = strtolower($_POST['username']);
		$encrypted_pass = encrypt_pass($_POST['password']);

		$prepquery = $db->prepare('SELECT COUNT(*) FROM users WHERE username = :username AND ecrypted_pass = :encrypted_pass)');
		$prepquery->bindParam(':username', $username);
		$prepquery->bindParam(':encrypted_pass', $encrypted_pass);
		$res = $prepquery->rowCount();

		return $res;
	}

	function encrypt_pass($password) {

		$Salt = uniqid();
		$Algo = '6';
		$Rounds = '7500';
		$cryptSalt = '$' . $Algo . '$rounds=' . $Rounds . '$' . $Salt;

		$encrypted_pass = crypt($password, $cryptSalt);

		return $encrypted_pass;

	}

	if(authenticate() > 0) {
		echo '<font face="Verdana" size="2">You are now logged in as ' . $username . '.';
		$_SESSION['is_logged_in'] = 1;
		$_SESSION['logged_in_as'] = $username;
	} else if(isset($_SESSION['is_logged_in'])) {
			echo '<font face="Verdana" size="2">You are already logged in';
	} else {
		echo '<font face="Verdana" size="2">The username or password was incorrect. <br /> ';
	}