[xsl] Determine last element before applu-templates

[gerritjan <gerritjankoekkoek@xxxxxxx>]

Hello,

Is there a 'best practise' for determine how many elements are in a 
document.
My schema looks like this:
	<xsd:element name = "onderwerpen">
		<xsd:complexType>
			<xsd:sequence>
				<xsd:element ref = "onderwerp"/>
			</xsd:sequence>
		</xsd:complexType>
	</xsd:element>
1 to many 'onderwerp' within 'onderwerpen'

My xslt looks like this:
<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"; 
version="1.0">
 <xsl:template match="onderwerpen">
   <xsl:apply-templates select="onderwerp">
     <xsl:with-param name="last_element">3</xsl:with-param>
   </xsl:apply-templates>
 </xsl:template>

 <xsl:template match="onderwerp">
   <xsl:param name="last_element"/>
   <xsl:if test="position()=$last_element">
     <xsl:text>Something specific for last element</xsl:text>
   </xsl:if>
 </xsl:template>
</xsl:stylesheet>

The hard-code '3' should be determined before; based on the number of 
elements 'onderwerp'
Any suggestions how this is best handled?

Gerritjan Koekkoek