How would I oput a random string of letters and #'s ?

[Conor]

Like I know I would have

$string="a b c d e f g h i j k l m n o p q r s t u v w x y z";
$array=explode(" ",$string);

but how would I output 5 random characters from that array

[sideshow]

http://www.phpfreaks.com/quickcode/Random_Password_Generator/56.php

[96turnerri]

<?php

$string = "a b c d e f g h i j k l m n o p q r s t u v w x y z";
$array = explode(" ",$string);
$rand_keys = array_rand($array, 5);
$pass = $array[$rand_keys[0]] . $array[$rand_keys[1]] . $array[$rand_keys[2]] . $array[$rand_keys[3]] . $array[$rand_keys[4]];
echo $pass;

?>