I am trying to compare two xml documents of the same format.  I have
successfully transformed the documents to include a field called ItemKey
which includes a unique key (comprised of four other elements).  I am
now trying to match and compare elements based on that key value.

My XSLT includes the following as "global" variables:

<xsl:variable name="file1">test_comp4.xml</xsl:variable>
<xsl:variable name="old_file"
select="document($file1)/*"></xsl:variable>
<xsl:variable name="file2">test_comp4_edited.xml</xsl:variable>
<xsl:variable name="new_file"
select="document($file2)/*"></xsl:variable>
<xsl:output method="xml" indent="yes"/>
<xsl:key name="test" match="//ItemKey" use="//ItemKey"/>

	Martin Honnen
	http://msmvps.com/blogs/martin_honnen/