Hi, I have 15 news in a nodeType called RunwayNews. I try to display a random one. It partly works, but sometimes it chooses nothing. Like if the random chooses 0 so it displays nothing. What I've done wrong?

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE xsl:stylesheet [ <!ENTITY nbsp "&#x00A0;"> ]>
<xsl:stylesheet
        version="1.0"
        xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
        xmlns:msxml="urn:schemas-microsoft-com:xslt"
        xmlns:msxsl="urn:schemas-microsoft-com:xslt"
        xmlns:bdk="http://bodenko.com"
        xmlns:umbraco.library="urn:umbraco.library"
        exclude-result-prefixes="msxml msxsl umbraco.library bdk">
        <xsl:output method="xml" omit-xml-declaration="yes" />

        <xsl:param name="currentPage" />

        <msxsl:script language="JavaScript" implements-prefix="bdk">
                function Random(r) { return Math.ceil(Math.random()*r); }
        </msxsl:script>

        <xsl:template match="/">      
                <xsl:variable name="newsNodes" select="$currentPage/ancestor-or-self::node[@level=1]/descendant-or-self::node[@nodeTypeAlias='RunwayNews']" />        
        <xsl:value-of select="$newsNodes[bdk:Random(count($newsNodes))]/data[@alias='textIntro']" disable-output-escaping="yes"/>
        </xsl:template>
</xsl:stylesheet>

Thanks for your help.