Converting entities into string

Hello list,

i need to convert a xml-file into another xml-file. I ran into this
problem:

Source XML:

<DESCR>
 some text
 <b>
   more text
 </b>
 even more text
</DESCR>

My Target XML should look like:

<DESCR>
 some text 
 &lt;b&gt;
   more text
 &lt;/b&gt;
 even more text
</DESCR>

i tried <xsl:copy-of> which gave me a copy of the source. <xsl:copy>
removed the <b>, but I want to keep the information about the <b>, just not
as <b>

In short: how can i convert the '<' and '>' into '&lt;' and '&gt;' easily?

Or is there another solution? 

Thanks for your help,
Christian

 XSL-List info and archive:  http://www.mulberrytech.com/xsl/xsl-list