<xsl:key name="class" match="class" use="@type"/>

<xsl:variable name="myVar">
  <xsl:for-each select="key('class', 'second')">
    <xsl:value-of select="@name" />
    <xsl:if test="position() != last()">#</xsl:if>
  </xsl:for-each>
</xsl:variable>

Jarno

 XSL-List info and archive:  http://www.mulberrytech.com/xsl/xsl-list