Quick background:
I am merging 4 xml documents into a PDF doc using xsl-fo and xslt.
I have one xml document containg filenames. XML file 1 contains
header information. XML file 2 contains addresses and
the XML file 3 contains detail items. What I want to do is loop through all
the header records. On each header select a matching address from file3
using an account number element value from file 1 and then select multiple
detail
records from file 2 using an id element value from file 1. My problem is 2
fold
1) the xml files returned from the database share the same top level
elements
<ROWSET> and <ROW> and the key elements have the same name in both
files, <ACCOUNT> and <SHIPID> so can I differentiate file1.rowset.row from
file2.rowset.row in my template match values?
2) The key is defined before the file variables so what can I use as a
match value.

My xml files look like this

<ROWSET>
  <ROW id="1">
    <A>xxxx</A>
    <B>yyyy</B>
    <C>zzzz</C>
  </ROW>
  <ROW id="2">
    ...
</ROWSET> where <B> is shared with file 1 & 2
and <C> is shared with file 2 & 3
Elements in file2 would be <B>, <D> and <E>
Elements in file3 would be <C>, <F> and <G>

My stylesheet looks like:

<xsl:stylesheet ... >
  <xsl:output method="html"/>
  <!-- key for file1 to file2 join -->
  <xsl:key name="acctkey" match="???//ROW" use="ACCOUNT"/>
  <!-- key to file1 to file3 join -->
  <xsl:key name="shipkey" match="???//ROW" use="SHIPID"/>

<!-- template for xml file name document -->
<xsl:template match="/xml-files">
  <xsl:variable name="headers" select="document(@file1)"/>
  <xsl:variable name="accounts" select="document(@file2)"/>
  <xsl:variable name="lineitems" select="document(@file3)"/>

<xsl:apply-templates select="$headers//ROW"/>

</xsl:template>

<!-- file1 ROW -->
<xsl:template match="???//ROW">  <!-- all forms of $headers gives invalid
token -->

  <xsl:apply-templates/>
</xsl:template>

...

<!-- template file1 account number -->
<xsl:template match="B"/>  <!-- match value? -->
  <xsl:value-of select="."/>
  <xsl:apply-templates select="key('acctkey', '.')"/>
</xsl:template>

<!-- template file1 account number -->
<xsl:template match="B"/>  <!-- match value? so file 1 <B> only -->
  <xsl:value-of select="."/>
  <xsl:apply-templates select="key('acctkey', '.')"/>
</xsl:template>

<!-- file 2 ROW -->
<xsl:template match="???//ROW">

  <xsl:value-of select="D"/>
  <xsl:value-of select="E"/>
</xsl:template>

</xsl:stylesheet>

Thanks,
Richard Shonk