Fwd: problem using the nodeset() extension function

<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
  xmlns:xsltc-extension="http://xml.apache.org/xalan/xsltc"
  xmlns:xalan="http://xml.apache.org/xalan"
  xmlns:exslt="http://exslt.org/common"
  version="1.0">
  <xsl:template match="/">
    <xsl:variable name="rtf">
      <docelem>
        <elem1>elem1</elem1>
        <elem2>elem2</elem2>
      </docelem>
    </xsl:variable>
    <!-- Use nodeset as an XSLTC extension function -->
    <xsl:value-of select="xsltc-extension:nodeset($rtf)/docelem/elem1"/>
    <!-- Use nodeset as a Xalan-Java extension function -->
    <xsl:value-of select="xalan:nodeset($rtf)/docelem/elem1"/>
    <!-- Use nodeset as an EXSLT extension function -->
    <xsl:value-of select="exslt:node-set($rtf)/docelem/elem1"/>
    <!-- Use nodeset as standard function -->
    <xsl:value-of select="nodeset($rtf)/docelem/elem1"/>
  </xsl:template>
</xsl:stylesheet>

Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.1_01-b01)
Java HotSpot(TM) Client VM (build 1.4.1_01-b01, mixed mode)

Thank you,
	Gregor