Need help with my PHP (Banned IP / Random Redirect) script

I've been working on a PHP script that will first look to see if a users IP is banned. If banned it redirects them to a predesignated URL. If not it redirects them to a diferent URL. Up to here I have gotten to work fine.

Want I want to do now is instead of sending the non banned users to just one URL, I am trying to have it send them to a randomly selected URL in an array. This is where I am having problems.

Below is an example of my code so far. Anyone see what I am doing wrong or have any suggestions on a better way to do this without using SQL?

<?php 
$banned_ip = array(); 
$banned_ip[] = '10.114.108.17'; 
$banned_ip[] = '10.100.46.10'; 
$banned_ip[] = '69.72.244.98'; 
$banned_ip[] = '167.206.128.131'; 
$banned_ip[] = '205.162.217.141'; 
$banned_ip[] = '76.90.3.205'; 
$banned_ip[] = '77.91.224.6'; 
$banned_ip[] = '82.80.249.145'; 

foreach($banned_ip as $banned) 
{  
    $ip = $_SERVER['REMOTE_ADDR']; 
    if($ip == $banned)
    {  
        header("location: http://www.ALL-BANNED-IPS-ARE-SENT-TO-THIS-URL.com"); 
        die();//abort the script on redirect. just in case.
    }
}  
//if the IP is not banned then I want people to be randomly sent to one of the URLs listed below
$urls = array("www.THIS-SITE.com", 
              "www.OR-THIS-SITE-1.com", 
              "www.OR-THIS-SITE-2.com", 
              "www.OR-THIS-SITE-3.com", 
              "www.OR-THIS-SITE-4.com", 
              "www.OR-THIS-SITE-5.com"); 
$url = $urls[array_rand($urls)]; 
header("location: http://$url"); 
?> 

Code (markup):

 

Something like :

$url[1] = 'http://www.THIS-SITE.com';
$url[2] = 'http://www.That-SITE.com';
$url[3] = 'http://www.SITE.com';
$url[4] = 'http://www.blahblah.com';

etc etc..
listing all random sites with a number.
Then run a random function to randomly grab one like this:

$i=rand(1,50);