comparing 2 childs of 2 childs

Hi all, my xml is representing a database structure.. and so it goes
like this:

    <DataSet>
        <DataTable TableName="tabela">
           <Column>
                <ColumnName>id</ColumnName>
           </Column> .. and then more columns

           <Foreign_Keys>
                <FK_COLUMN_NAME>CO</FK_COLUMN_NAME>
                  .. then even more childs.. 
           </Foreign_Keys>
                and more foreing keys.. 
Anyway.. the point is that i want for each Column.. to compare with
the all Foreign_Keys/FK_COLUMN_NAME and then if is equal print
something... in case he doesn't find one column that doesn't match any
foreign_key it means is not a foreign key so prints another thing...
Anyone has good ideas? I did something like this... maybe you can
change it and then give me an ideia
        
<xsl:template name="ListagemValores">
     <xsl:param name="thisField"/>
         <xsl:for-each select="$thisField/Column">
          <TD>
            <xsl:variable name="coluna">
                <xsl:value-of select="ColumnName"/>
            </xsl:variable>                                
                    
            <xsl:for-each select="../Foreign_Keys">
             <xsl:choose>
                <xsl:when test="FK_COLUMN_NAME = $coluna">
                 <db:dataLabel fieldName="{$coluna}">
                    <db:tableData name="list_{FK_NAME}"
foreignTable="{PK_TABLE_NAME}" visibleFields="descricao"
storeField="{PK_COLUMN_NAME}"/></db:dataLabel>
                </xsl:when>
                <xsl:otherwise>
                <!-- <db:label fieldName="{$coluna}" />-->
                </xsl:otherwise>
              </xsl:choose>
           </xsl:for-each>
                                
            </TD>
   </xsl:for-each>
</xsl:template>

Thanks 
Andri Moniz