How to use "if" condition?

[Jennifer2010]

I have a plugin that inserts PHP code on all pages to check a user's IP address. What I want to do exclude it from checking administrator's IPs.

The plugin looks like this:

	<dependencies />
	<codes />
	<templates />
	<plugins>
		<plugin active="1" executionorder="1">
			<title>BlockScript vBulletin Integration</title>
			<hookname>init_startup</hookname>
			<phpcode><![CDATA[if (file_exists(CWD.'/blockscript/detector.php')) {
	include_once(CWD.'/blockscript/detector.php');
} elseif (file_exists(CWD.'/../blockscript/detector.php')) {
	include_once(CWD.'/../blockscript/detector.php');
} else {
	include_once(CWD.'/../../blockscript/detector.php');
}]]></phpcode>
		</plugin>
	</plugins>
	<phrases />
	<options />
	<helptopics />
	<cronentries />
	<faqentries />
</product>

And the if condition I'd like to use is this:
<vb:if condition="is_member_of($bbuserinfo, 1,2,3,4,8,17,19,20,26,15,22,16,14,18,21)">

But if I insert that in the xml file when adding the product/plugin it gives me a mysql error and doesn't work.

Any ideas?

Thank you!
-Jennifer