<xsl:if test="count(preceding-sibling::row) mod 2 = 0">
    ...
</xsl:if>

          <xsl:if test="(position() mod 2) = '0' ">
               <xsl:attribute name="background-color">
                    <xsl:value-of select="$row_color_gray"/>
               </xsl:attribute>
          </xsl:if>

this doesn't work properly, becouse position() begin at 1 for each group,
so I
get sometimes the same color for the last row of a group and the first one
of the next group.

thanks,

Robert.

System Development
VIRBUS AG
Fon  +49(0)341-979-7411
Fax  +49(0)341-979-7409
joerg.heinicke@xxxxxxxxx
www.virbus.de