Gettting Dns

[heeha]

I was trying to get dns_AAAA for ipv6 but i do not get the any result, I only get ouput as "array() " in the page. 

$a = dns_get_record("example.com", DNS_AAAA);
print_r($a); 

doesnt output the ipv6, it only gets the "array()";