to validate a specific value, you would amend the code to this:
<?php echo(((isset($_POST['callMe']) && $_POST['callMe'] == "NY")?$_POST['phoneNumber']:"(222) 222-2222")); ?>
in this example, it is using phone number validation, so a valid phone number needs to be passed as the conditional validation. If it where using Required validation, than a string would need to be used.
the code you provided is for client side validation. we dont use client side validation in the current version of super suite since it is easily disabled by disabling javascript in the browser, you should use server side validation instead.