If I have the following xml:

<?xml version="1.0"?>
<addresses>
    <address country="Italy">
        <tag name="street" flag="5">One Microsoft Way</tag>
        <tag name="number">1</tag>
        <tag name="city">Redmond</tag>
        <tag name="state" unit="25">WA</tag>
        <tag name="zip">98052</tag>
    </address>
    <address country="France">
         <section type="Condo" Comp="1">
              <tag name="street">15 Mako Place</tag>
              <tag name="number">1545</tag>
              <tag name="city">Fargo</tag>
              <tag name="state" unit="10">Paris</tag>
              <tag name="zip">10110</tag>
         </section>
    </address>
</addresses>

Where one section is addresses/address/tag and another is 
addresses/address/section/tag, I want to be able to get the country from the 
address.

Nomrally I would just do

<xsl:value-of select="ancestor::address/@country"/>

But if I have a "section", I would need to go up 2 levels.

My current xsl is:

<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
                 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
   <xsl:output method="xml" indent="yes"/>
   <xsl:template match="addresses">
        <dataset>
             <xsl:apply-templates/>
        </dataset>
   </xsl:template>
 <xsl:template match="tag|section/tag">
     <address>
          <sectionNumber>
                <xsl:value-of select="ancestor::section/@Comp"/>
           </sectionNumber>
           <name>
                  <xsl:value-of select="@name"/>
           </name>
           <flag>
                <xsl:if test="not(@flag)">
                      <xsl:attribute name="xsi:nil">true</xsl:attribute>
                </xsl:if>
                <xsl:value-of select="@flag"/>
           </flag>
          <unit>
                <xsl:if test="not(@unit)">
                       <xsl:attribute name="xsi:nil">true</xsl:attribute>
                </xsl:if>
                <xsl:value-of select="@unit"/>
          </unit>
         <value>
              <xsl:value-of select="."/>
         </value>
     </address>
 </xsl:template>
</xsl:stylesheet>

I would like to add a section:

          <country>
                <xsl:value-of select="ancestor::address/@country"/>
           </country>

but this won't work for both cases.

I could set up 2 template sections, but I would prefer to do this with some 
sort of if statement but am not sure how to set it up.

Also, do I need the if test="not(@unit)" test in the following code?  If I 
don't have it, it still seems to work.

          <unit>
                <xsl:if test="not(@unit)">
                       <xsl:attribute name="xsi:nil">true</xsl:attribute>
                </xsl:if>
                <xsl:value-of select="@unit"/>
          </unit>

Thanks,

Tom