Pronounceable password generator

pronounceable_passwords.php

<?php

function makeRandomPassword() {
        $vowels = "aeiou";
        $consonants = "bcdfghjklmnpqrstvwxyz";
        $numbers = "0123456789";
        srand((double)microtime()*1000000);
        $i = 0; // # of chars;
        $j=0; // Position. 0=consonant, 1 & 2 = vowels
        while ($i <= 6) {
                if ($j==0) { 
                        $num = rand() % 21;
                        $tmp = substr($consonants, $num, 1);
                } else {
                        $num = rand() % 5; 
                        $tmp = substr($vowels, $num, 1); 
                }
                $pass = $pass . $tmp; 
                $i++;   
                $j++;                if ($j>2) {
                $j=0;
        }       }                     

        			    $num = rand() % 10;
                        $tmp = substr($numbers, $num, 1);
                        $pass = $pass . $tmp;
                                                $num = rand() % 10;
                        $tmp = substr($numbers, $num, 1);
                        $pass = $pass . $tmp;
return $pass;           
}    


echo makeRandomPassword();

?>