Grouping with keys or xpath

Hello,
I have achived to group my xml input(see further down) to the desired output (see further down) 
with with xsl file (see further down) using xpath, but I have not manage to do the same with keys and the key function. The problem
is that the key is global for the whole document. I only want to group each articlerow in one variant at time.
Any hint/help would be appreciated

Best regards
 
Uffe



The xml file
<doc>
	<variant>
		<articlerow>
			<nev_article_pos>1</nev_article_pos>
			<article>
				<nev_article>009504145</nev_article>
			</article>
		</articlerow>
		<articlerow>
			<nev_article_pos>12</nev_article_pos>
			<article>
				<nev_article>009504145</nev_article>
			</article>
		</articlerow>
		<articlerow>
			<nev_article_pos>12</nev_article_pos>
			<article>
				<nev_article>009504145</nev_article>
			</article>
		</articlerow>
		<parttitle>Hello World</parttitle>
		<articlerow>
			<nev_article_pos>18</nev_article_pos>
			<article>
				<nev_article>009504145</nev_article>
			</article>
		</articlerow>
		<articlerow>
			<nev_article_pos>19</nev_article_pos>
			<article>
				<nev_article>009504145</nev_article>
			</article>
		</articlerow>
		<articlerow>
			<nev_article_pos>19</nev_article_pos>
			<article>
				<nev_article>009504145</nev_article>
			</article>
		</articlerow>
	</variant>
	<variant>
		<articlerow>
			<nev_article_pos>4</nev_article_pos>
			<article>
				<nev_article>009504145</nev_article>
			</article>
		</articlerow>
		<parttitle>Hello World</parttitle>
		<articlerow>
			<nev_article_pos>6</nev_article_pos>
			<article>
				<nev_article>009504145</nev_article>
			</article>
		</articlerow>
		<articlerow>
			<nev_article_pos>4</nev_article_pos>
			<article>
				<nev_article>009504145</nev_article>
			</article>
		</articlerow>
		<articlerow>
			<nev_article_pos>18</nev_article_pos>
			<article>
				<nev_article>009504145</nev_article>
			</article>
		</articlerow>
		<articlerow>
			<nev_article_pos>19</nev_article_pos>
			<article>
				<nev_article>009504145</nev_article>
			</article>
		</articlerow>
		<articlerow>
			<nev_article_pos>19</nev_article_pos>
			<article>
				<nev_article>009504145</nev_article>
			</article>
		</articlerow>
	</variant>
</doc>

The output

<document>
	<partinfo>
		<partlist>
			<partcallout>
				<calloutitem>1</calloutitem>
				<article>009504145</article>
			</partcallout>
			<partcallout>
				<calloutitem>12</calloutitem>
				<article>009504145</article>
				<article>009504145</article>
			</partcallout>
			<title>Hello World</title>
			<partcallout>
				<calloutitem>18</calloutitem>
				<article>009504145</article>
			</partcallout>
			<partcallout>
				<calloutitem>19</calloutitem>
				<article>009504145</article>
				<article>009504145</article>
			</partcallout>
		</partlist>
		<partlist>
			<partcallout>
				<calloutitem>4</calloutitem>
				<article>009504145</article>
				<article>009504145</article>
			</partcallout>
			<title>Hello World</title>
			<partcallout>
				<calloutitem>6</calloutitem>
				<article>009504145</article>
			</partcallout>
			<partcallout>
				<calloutitem>18</calloutitem>
				<article>009504145</article>
			</partcallout>
			<partcallout>
				<calloutitem>19</calloutitem>
				<article>009504145</article>
				<article>009504145</article>
			</partcallout>
		</partlist>
	</partinfo>
</document>

The xsl file
<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"  xmlns:nevis="http://www.volvo.com/namespaces/processing" xmlns:xlink = "http://www.w3.org/1999/xlink">
	<xsl:strip-space elements="*"/>
	<xsl:template match="/doc">
		<document>				
			<partinfo>
				<xsl:apply-templates select="variant"/>
			</partinfo>	
		</document>
	</xsl:template>
		
	<xsl:template match="variant">
		<partlist>
			<xsl:apply-templates/>
		</partlist>
	</xsl:template>
	
	<xsl:template match="articlerow">
		<xsl:for-each select="self::*[not(nev_article_pos = preceding-sibling::articlerow/nev_article_pos)]">
			<partcallout>
				<calloutitem><xsl:value-of select="nev_article_pos"/></calloutitem>
				<xsl:apply-templates select="./..//article[current()/nev_article_pos =./../nev_article_pos]"/>
			</partcallout>	
		</xsl:for-each>
	</xsl:template>
	
	<xsl:template match="parttitle">
		<title>
			<xsl:value-of select="."/>
		</title>
	</xsl:template>
	
	<xsl:template match="article">
		<article><xsl:value-of select="nev_article"/></article>
	</xsl:template>
	
	<xsl:template match="text()"/>
</xsl:stylesheet>


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