I have XML like,

<items> 
  <item> 
    <products> 
      <product>laptop</product> 
      <product>charger</product> 
      <product>Cam</product>
    </products> 
  </item> 
  <item> 
    <products> 
      <product>laptop</product> 
      <product>headphones</product>  
      <product>Photoframe</product>  
    </products>   
  </item> 
  <item> 
    <products> 
      <product>laptop</product> 
      <product>charger</product>
      <product>Battery</product>   
    </products>   
  </item> 
</items> 

and I am using xslt on it

//can't change xpath as getting it from somewhere else

<xsl:param name="xparameter" select="items/item[products/product='laptop' and products/product='charger']"></xsl:param>

    <xsl:template match="/">

        <xsl:for-each select="$xparameter">

          <xsl:for-each select="products/product[not(.=preceding::product)]">
              <xsl:sort select="."></xsl:sort>
              <xsl:value-of select="." ></xsl:value-of>,
          </xsl:for-each>

          </xsl:for-each>

    </xsl:template>

I want the output to be

laptop
charger
cam
Battery

But I m not getting the result as I m expecting...distinct values is working fine ..something is getting wrong when I am adding that and claus