Hello

I am having a problem with niceUrl, I have defined two variables which stores the id and node name of an ancestor node. I do not get an error when saving, just an error when trying to render the macro content. Any help would be appreciated.

<xsl:template name="listContributors">
    <xsl:variable name="blogPostNodeSet">
    <xsl:for-each select="$currentPage/descendant-or-self::node[@ nodeTypeAlias='BlogPost']">
            <xsl:sort order="descending" select="@createDate" />
            <xsl:if test="position() &lt; $numOfBlogs">
                <xsl:copy-of  select="." />
            </xsl:if>
        </xsl:for-each>
    </xsl:variable>   
    <ul>
        <xsl:for-each select="msxsl:node-set($blogPostNodeSet)/node[not(@writerID = preceding-sibling::node/@writerID)]">
            <xsl:variable name="blogParent" select="ancestor::node[@nodeTypeAlias='Blog']/@id" />
            <xsl:variable name="blogParentName" select="ancestor::node[@nodeTypeAlias='Blog']/@nodeName" />   
            <li>
                <a>
                    <xsl:attribute name="href">
                        <xsl:value-of select="umbraco.library:NiceUrl($blogParent)"/>   
                    </xsl:attribute>   

                    <xsl:value-of select="$blogParentName"/>
                </a>
            </li>
        </xsl:for-each>
    </ul>
</xsl:template>