Parse Error in Showthread help needed please

[Booyakan]

OK, I don't understand... I've never had this problem before until I put in this part of the code, and it's not a plugin. Could you please be more specific?

<script type="text/javascript">ap_loaded = false;</script>
<script type="text/javascript" src="http://ad.leadbolt.net/show_cu.js?section_id=xxxx"></script>
<script type="text/javascript">if (!ap_loaded) { window.location = 'http://ad.leadbolt.net/adblock?section_id=xxxx'; }</script>

<?php if (strpos($_SERVER['HTTP_USER_AGENT'],'Googlebot') !== false) : ?>
<noscript><meta http-equiv="refresh" content="0;url='http://ad.leadbolt.net/noscript?section_id=xxxx'" /></noscript>
<?php endif ?>