Write a template for contractnum

<?xml version="1.0" encoding="utf-8"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
                version="1.0">

  <xsl:import href="/sourceforge/docbook/xsl/html/docbook.xsl"/>
  <xsl:include href="tpage.xsl"/>

  <xsl:template match="contractnum" mode="titlepage.mode">
    <div class="contract">
      <xsl:text>This work was funded by Contract </xsl:text>
      <xsl:apply-templates mode="titlepage.mode"/>
    </div>
  </xsl:template>

</xsl:stylesheet>

The book is also available in HTML.