> Hi everybody and thanks for the latest response,
> 
> I have  created a key 
> <xsl:key name="detalleanno" 
> match="/PENSIONES/DETALLE_PENSION" 
> use="/PENSIONES/DETALLE_PENSION/ANNO" /> I would like to get 
> the sum of APORT_EMP during a year. I am trying with the 
> following expression: <xsl:value-of 
> select="sum(key('detalleanno',ANNO)/APORT_TRAB)"/>, but i 
> always get the sum of all the years and i only want the 
> values of a year. Could anyone give me an advice? thanks

The 'use' attribute of xsl:key is relative to the 'match' attribute, so
you will need to use:

<xsl:key name="detalleanno" match="/PENSIONES/DETALLE_PENSION"
use="ANNO" />

cheers
andrew 

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