Nestled <xsl:choose>

I'm trying to create a testing structure to assign a different template
depending on the content of the element attributes "variant" & "style".
in pseudo code:
---------------------------------
if variant = book
    then
            if style = fiction
                use fiction template
            else
                use non-fiction template
            endif
    elseif variant = graphic novel
        use graphic novel template
    elseif variant = magazine
        use magazine template
    else
        show error massage
endif
---------------------------------
Is this possible in xsl?
Or should I create a separate template to test the "fiction" attribute.

Here's the xsl code that I'm using.
<!--CHECK VARIANT-->
<xsl:attribute name="variant">
    <xsl:choose>
        <!--BOOK VARIANT-->
        <xsl:when test="variant = 'Book'">
            <!--CHECK STYLE-->
            <xsl:attribute name="style">
                <xsl:choose>
                    <!--FICTION STYLE-->
                    <xsl:when test="style = 'Fiction'">
                        <xsl:for-each select="fiction">
                            <xsl:apply-templates select="." />
                        </xsl:for-each>
                    </xsl:when>
                    <!--END FICTION STYLE-->
                    <!--NON-FICTION STYLE-->
                    <xsl:otherwise>
                        <xsl:for-each select="non-fiction">
                            <xsl:apply-templates select="." />
                        </xsl:for-each>
                     </xsl:otherwise>
                    <!--END NON-FICTION STYLE-->
                </xsl:choose>
            </xsl:attribute>
            <!--END CHECK STYLE-->
        <!--END BOOK VARIANT-->
        </xsl:when>
            <!--GRAPHIC_NOVEL VARIANT-->
            <xsl:when test="variant = 'Graphic_Novel'">
                <xsl:for-each select="graphic_novel">
                    <xsl:apply-templates select="." />
                </xsl:for-each>
            </xsl:when>
            <!--END GRAPHIC_NOVEL VARIANT-->
            <!--MAGAZINE VARIANT-->
            <xsl:when test="variant = 'Magazine'">
                <xsl:for-each select="magazine">
                    <xsl:apply-templates select="." />
                </xsl:for-each>
            </xsl:when>
            <!--END MAGAZINE VARIANT-->
            <!--ERROR TRAP-->
            <xsl:otherwise>
                <xsl:text>Error</xsl:text>
            </xsl:otherwise>
            <!--END ERROR TRAP-->
    </xsl:choose>
</xsl:attribute>
 <!--END CHECK VARIANT-->

Thanks,
            Oliver

p.s. does this list have a tip harvester or something similar?


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