> But please allow me one more question. Is there a way to get 
> the sum result into a variable or parameter? I would need the 
> sum for further more calculations...
> 

<xsl:variable name="total">
  <xsl:call-template name="xyz">
    <xsl:with-param...
  </xsl:call-template>
</xsl:variable>

Michael Kay
http://www.saxonica.com/