I could  able to solve it
<xsl:variable name="purchaseTotalLength">
<xsl:for-each
select="exslt:node-set($purchaseTotalcount)/*">
	<sub>
		<xsl:copy-of select="@val"/>
	</sub>
</xsl:for-each>
</xsl:variable>
<xsl:value-of
select="sum(exslt:node-set($purchaseTotalLength)/sub)"/>

Still I am not sure why xsl-copy is not working?

thanks
-Ranjan



		
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