> If your code isn't working and you want to know why, it's usually best to
> show us your code.
>

Thanks! It's here:

<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:qp="http://epecis/queryparams"
xmlns:xalan="http://xml.apache.org/xalan"
exclude-result-prefixes="xalan">

 <xsl:param name="params" />

 <xsl:template match="@* | node()">
  <xsl:copy>
    <xsl:apply-templates select="@* | node()"/>
  </xsl:copy>
 </xsl:template>

 <xsl:template match="*[local-name()='param']">

  <xsl:choose>
    <xsl:when test="@name = xalan:nodeset($params)/query-params/param/@name">
      <xsl:value-of
select="xalan:nodeset($params)/query-params/param[@name=current()/@name]/@value"/>
    </xsl:when>
    <xsl:otherwise>
      <xsl:value-of select="."/>
    </xsl:otherwise>
  </xsl:choose>

 </xsl:template>

</xsl:stylesheet>

------------

Tried with and without xalan:nodeset extension. The result is the
same: It fails with the following exception:

java.lang.RuntimeException: Invalid conversion from node-set' a
'org.apache.xmlbeans.impl.store.Xobj$DocumentXobj.
	at com.sun.org.apache.xalan.internal.xsltc.runtime.BasisLibrary.runTimeError(BasisLibrary.java:1496)
	at com.sun.org.apache.xalan.internal.xsltc.runtime.BasisLibrary.runTimeError(BasisLibrary.java:1504)
	at com.sun.org.apache.xalan.internal.xsltc.runtime.BasisLibrary.nodesetF(BasisLibrary.java:499)
	at EmbedParametersFromUri.template$dot$1()
	at EmbedParametersFromUri.applyTemplates()
	at EmbedParametersFromUri.template$dot$0()
	at EmbedParametersFromUri.applyTemplates()
	at EmbedParametersFromUri.template$dot$0()
	at EmbedParametersFromUri.applyTemplates()
	at EmbedParametersFromUri.template$dot$0()
	at EmbedParametersFromUri.applyTemplates()
	at EmbedParametersFromUri.template$dot$0()
	at EmbedParametersFromUri.applyTemplates()
	at EmbedParametersFromUri.applyTemplates()
	at EmbedParametersFromUri.transform()
	at com.sun.org.apache.xalan.internal.xsltc.runtime.AbstractTranslet.transform(AbstractTranslet.java:602)
	at com.sun.org.apache.xalan.internal.xsltc.trax.TransformerImpl.transform(TransformerImpl.java:710)
	at com.sun.org.apache.xalan.internal.xsltc.trax.TransformerImpl.transform(TransformerImpl.java:313)
	at com.bea.wli.sb.resources.xslt.XsltExecutor.execute(XsltExecutor.java:153)