Hi all wonder if someone can help, i'm getting the following error on pages that aren't the top page, so sub pages of the top level pages. Don't really see whats wrong with it, so if anybody could have a look, i would be most greatful!

<ul>
<xsl:if test="$currentPage/ancestor-or-self::node/data[@alias='caseStudyIcon1'] != ''
or $currentPage/ancestor-or-self::node/data[@alias='caseStudyHeader1'] != ''
or $currentPage/ancestor-or-self::node/data[@alias='caseStudyLinkHeader1'] != ''
or $currentPage/ancestor-or-self::node/data[@alias='caseStudyLink1'] != ''">
<div class="rightColCaseStudiesContainer">
<li class="caseStudyIcon1"><img src="{umbraco.library:GetMedia($currentPage/ancestor-or-self::node/data[@alias='caseStudyIcon1'], 'false')/data [@alias = 'umbracoFile']}" alt="Icon"/></li>
<li class="caseStudy1"><xsl:value-of select="$currentPage/ancestor-or-self::node/data[@alias='caseStudyHeader1']"/><br />
<a href="{umbraco.library:NiceUrl($currentPage/ancestor-or-self::node/data[@alias='caseStudyLink1'])}" title="{$currentPage/ancestor-or-self::node/data[@alias='caseStudyLinkHeader1']}">
<strong><xsl:value-of select="$currentPage/ancestor-or-self::node/data[@alias='caseStudyLinkHeader1']"/></strong></a></li>
</div>
</xsl:if>
</ul>