/lib/jquery-validate/demo/milk/emails.php

<?php

$request = trim(strtolower($_REQUEST['email']));

$emails = array('glen@marketo.com', 'george@bush.gov', 'me@god.com', 'aboutface@cooper.com', 'steam@valve.com', 'bill@gates.com');

$valid = 'true';

foreach($emails as $email) {

	if( strtolower($email) == $request )

		$valid = '"Thats already taken."';

}

echo $valid;

?>