How to retain subtree elements while using sub-string

Hello,

I have a template where i am trying to restrict the string length
using sub-string. My string has subtree elements (mostly html tags
like <b>, <sup> etc) and i want to retain them as it is. I use
copy-of but found i loose the subtree elements when using sub-string
-  i mean this results in an html output having no <b>, <sup> or any
other subtree elements - while the content within them gets thro!. I
retain subtree elements if i just use copy-of WITHOUT sub-string. 

sample string:
In this session we <sub>this</sub><b>Bold</b> take a closer look at
what is meant by strategy. ... big para content

I get:
In this session we thisBold take a closer look at what is meant by
strategy...

What i want (same as input string):
In this session we <sub>this</sub><b>Bold</b> take a closer look at
what is meant by strategy...


In my xsl i pass my content to a trimPara template whenever i have to
restrict the length like:

	<xsl:template name="trimPara">
		<!-- pass the string to be cropped with required string length -->
		<xsl:param name="stringLenRequired"/>
		<xsl:param name="stringInput"/>
		<xsl:copy-of select="$stringInput"/> <!-- this retains subtree
elements here, while i lose them in below 

statemments where i use sub-string, which i have to do -->
		<xsl:copy-of
select="substring($stringInput,1,number($stringLenRequired))"/>
		<xsl:copy-of 

select="substring-before(concat(substring($stringInput,number($stringLenRequired)+1,number($stringLenRequired)
+20),' ' ),' 

')"/> <!-- to make it a full word -->
		<xsl:if test="string-length($stringInput) >
number($stringLenRequired)">...</xsl:if>
	</xsl:template>

Pls suggest me how can i retain the subtree elements while using
sub-string. Are there any other method i can acheive this? Thanks in
adv

karl


Send instant messages to your online friends http://uk.messenger.yahoo.com