Social Insurance Numbers

<?php
    /*
    PHP Library - Social Insurance Number-related functions
    
    Copyright (c) 2009, reusablecode.blogspot.com; some rights reserved.
    
    This work is licensed under the Creative Commons Attribution License. To view
    a copy of this license, visit http://creativecommons.org/licenses/by/3.0/ or
    send a letter to Creative Commons, 559 Nathan Abbott Way, Stanford, California
    94305, USA.
    */
 
    // Format a Social Insurance Number.
    function formatSIN($socialInsuranceNumber)
    {
        if (eregi("^(\d{3})[\-\s]?(\d{3})[\-\s]?(\d{3})$", $socialInsuranceNumber))
        {
            return eregi_replace("^(\d{3})[\-\s]?(\d{3})[\-\s]?(\d{3})$", "$1 $2 $3", $socialInsuranceNumber);
        }
        else
        {
            die("Input cannot be formatted as a social insurance number.");
        }
    }
 
    // Validate a Social Insurance Number.
    // REQUIRES: luhn()
    function isValidSIN($socialInsuranceNumber)
    {
        return (eregi("^([1-79]{3})[\-\s]?(\d{3})[\-\s]?(\d{3})$", $socialInsuranceNumber) && luhn($socialInsuranceNumber)) ? true : false;
    }
 
?>