[xsl] Question on preceding Text()

["Besi Fube" <pearle20@xxxxxxxxxxx>]

I am currently attempting to Wrap nodes within a center para into one center 
tag by checking the length of the preceding sibling. If the length of the 
preceding sibling is greater than Zero, then a center tag has already been 
opened so nothing needs to be done. Otherwise open a center tag. I have 
included a test xml structure and a portion of the xslt that attempts to 
handle this. I am using the same reverse logic to close the <Center> tag. 
i.e string-length(parent::*/following-sibling::*)>0

The problem I seem to be having with this is that text() for instance the 
text "Chapter on Testing:" can not be considered a preceding-sibling of 
<AddText>Testing FAQ</AddText> even though they have the same <Center> 
parent tag since preceding-sibling does not grab the text node.

Is there a better way of checking the length of the closest preceding text 
node that is a 'sibling' of the context node?

I attempted using
string-length(parent::*/preceding::*[1])>0
but this does not ensure that I am pulling a node that is a child of the 
same parent node. When I try using the reverse i.e 
string-length(parent::*/following::*[1])>0 to close the center tag, the tag 
closes right after the first text(), in this case after the sentence 
"Chapter on Testing:"

Thanks, I will very much appreciate any suggestions.
Besi

***********************************************
<Book>
	<TitleHead>
		<TitleNum>
			Chapter 1.
		</TitleNum>
		<Center>
			Chapter on Testing:
			<AddText>Testing FAQ</AddText>
			<StrikeText>Questions</StrikeText>
		</Center>
	</TitleHead>
</Book>



***********************************************
<?xml version="1.0"?>
<xsl:stylesheet version="1.0" 
xmlns:xsl="http://www.w3.org/1999/XSL/Transform";>

<xsl:output method="text"/>
<!--Wrap Center child tags by check if the length of preceding sibling of 
Text parent nodes such as AddText and Strike Text within the Center tags is 
zero-->
<xsl:template match="text()">
	<xsl:if test="ancestor::Center">
		<xsl:choose>
			<xsl:when test ="name(../..)='Center' and 
string-length(parent::*/preceding-sibling::*)>0">
				<xsl:text> </xsl:text>
			</xsl:when>
			<xsl:otherwise>
				<xsl:text disable-output-escaping='yes'>&lt;center&gt;</xsl:text>
			</xsl:otherwise>
		</xsl:choose>
	</xsl:if>
</xsl:template>
</xsl:stylesheet>