My XSL is like below:

<xsl:template match="grant-sponsor">
		<grant-sponsor id="grs{position() - 1}">
			<xsl:apply-templates/>
		</grant-sponsor>
	</xsl:template>
	<xsl:template match="grant-number">
		<grant-number refid="{preceding-sibling::grant-sponsor/@id}">
			<xsl:apply-templates/>
		</grant-number>
	</xsl:template>

I am getting the empty refid.

  <xsl:template match="grant-sponsor">
    <grant-sponsor id="{generate-id()}">
      <xsl:apply-templates/>
    </grant-sponsor>
  </xsl:template>

	Martin Honnen
	http://msmvps.com/blogs/martin_honnen/