[xsl] Got xml base path in the xslt file

[Dongsheng Song <dongsheng.song@xxxxxxxxx>]

Hi all,
I use a xsl file to merge multiple xml files,  the master xml file like this:

<doc>
	<doc id="Intro" />
	<doc id="Configuration" />
	<doc id="Index" />
</doc>


The xsl file like this:

<xsl:for-each select="doc/doc">
    <xsl:variable name="fileName"><xsl:value-of select="@id"
/><xsl:text>.xml</xsl:text></xsl:variable>

    <xsl:for-each select="document($fileName)">
        <xsl:copy-of select="doc/div"/>
    </xsl:for-each>
</xsl:for-each>

Because the file path is relative of  the xsl file for 'document'
function, I have to put xsl and xml files together.
Can I got the base path of master xml file, so I can store xsl and xml
file separately?

Regards,
Dongsheng Song