Try this

<tr>
<xsl:if test="position() mod 2 = 0">
<xsl:attribute name="class">rowdark</xsl:attribute>
</xsl:if>
<td></td>
</tr>

> How can i create a counter into xsl due to insert alternate color in
> table-row???

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