List of IF Conditions

[RonJH]

Back again with a question regarding this code:

if ($vbulletin->userinfo['styleid'] == '15')
{
include(DIR . '/home/osorg/public_html/include/head.inc.php');
}

It works, but now I have two forum ID's which I wish to apply this to. I have tried:

if ($vbulletin->userinfo['styleid'] == '15,17')
{
include(DIR . '/home/osorg/public_html/include/head.inc.php');
}

It does not work. Any ideas?