zipcode checker

<?php
	require_once('mysql.class.php');

	//	CHANGE THESE TO VALID FOR YOUR
	//	MYSQL CONNECTION DETAILS
	$host = 'localhost';
	$user = 'db_user';
	$pass = 'password';
	$db = 'db_name';
	//	CHANGE THESE TO VALID FOR YOUR
	//	MYSQL CONNECTION DETAILS

	$redirect_unique = 'redir_a.htm';	//	Site to redirect to when the zip-code is not present in the db
	$redirect_exists = 'redir_b.htm';	//	Site to redirect to when the zip-code is present in the db

	if (isset($_POST['zipcode'])) {
		$zip = $_POST['zipcode'];

		$conn_params = array (
			'host' => $host,
			'user' => $user,
			'pass' => $pass,
			'db' => $db
		);
		$conn = new mysql($conn_params);

		$result = $conn->select(array('table' => 'zipcodes', 'condition' => 'zipcode = "'.$zip.'"', 'limit' => 1));
		if (count($result) == 0) {

			$conn->insert('zipcodes', array('zipcode' => $zip));
			header('Location: '.$redirect_unique);
			die();
		} else {
			header('Location: '.$redirect_exists);
			die();
		}
	}
?>