Generate complex random password in PHP

generatePassword.php

<?php
/**
 * Generate random password
 * @param int $length [optional] [default 9] length password to be generated
 * @return string
 * @link  http://www.webtoolkit.info/php-random-password-generator.html
 * @since 12/1/12 11:30 AM
 */
function generatePassword($length = 9) {
    $vowels = 'aeuy';
    $consonants = 'bdghjmnpqrstvz';
    $consonants .= 'BDGHJLMNPQRSTVWXZ';
    $vowels .= "AEUY";
    $consonants .= '23456789';
    $consonants .= '@#$%';

    $password = '';
    $alt = time() % 2;
    for ($i = 0; $i < $length; $i++) {
        if ($alt == 1) {
            $password .= $consonants[(rand() % strlen($consonants))];
            $alt = 0;
        } else {
            $password .= $vowels[(rand() % strlen($vowels))];
            $alt = 1;
        }
    }

    return $password;
}