e name="val">
            <xsl:if test = ".=''">
                <xsl:value-of select="'null'"/>
            </xsl:if>
            <xsl:if test = "number(text()) = text()">
                <xsl:value-of select="text()"/>
            </xsl:if>
            <xsl:if test = "number(text()) != text()">
                <xsl:value-of select="concat($quot, text(), $quot)"/>
            </xsl:if>
        </xsl:variable>
        <xsl:value-of select="concat($quot, preceding-sibling::index,
                                     $quot,':', $val)"/>
        <xsl:if test="preceding-sibling::index != //row[last()]/index">
            <xsl:text>,</xsl:text>
        </xsl:if>
    </xsl:template>
</xsl:stylesheet>r