php random password generator

function auth_pwgen(){
  $pw = '';
  $c  = 'bcdfghjklmnprstvwz'; //consonants except hard to speak ones
  $v  = 'aeiou';              //vowels
  $a  = $c.$v;                //both

  //use two syllables...
  for($i=0;$i < 2; $i++){
    $pw .= $c[rand(0, strlen($c)-1)];
    $pw .= $v[rand(0, strlen($v)-1)];
    $pw .= $a[rand(0, strlen($a)-1)];
  }
  //... and add a nice number
  $pw .= rand(10,99);

  return $pw;
}

php