When using XSL to transform XML for InDesign, How do I get the bold to output

Thank you in advance for any help you can provide.

I have an XML document provided to me,  here's a snippet:

<?xml version="1.0" standalone="no"?>
<web-export>
<?whitespace-handling use-characters?>
<run-date>02/10/2011
<pub-code>UNG VP
<ad-type>CLS 6 Col Tab
<cat-code>Liner</cat-code>
<class-code>100</class-code>
<subclass-code>143</subclass-code>
<position-description>Notices</position-description>
<ad-number>0000146752-01</ad-number>
<start-date>02/10/2011</start-date>
<end-date>02/10/2011</end-date>
<line-count>6</line-count>
<run-count>1</run-count>
<customer-type>Transient</customer-type>
<account-number>151915</account-number>
<account-name>OREGON WCP STATEWIDE CLASS</account-name>
<addr-1>133 ENTERPRISE DRIVE </addr-1>
<addr-2> </addr-2>
<city>VERONA</city>
<state>WI</state>
<postal-code>53593</postal-code>
<country>USA</country>
<phone-number>6081111111</phone-number>
<fax-number></fax-number>
<url-addr></url-addr>
<email-addr></email-addr>
<pay-flag>N</pay-flag>
<ad-description>ATTENTIONDIABETICSWITHMEDICAREGETAFREETA</ad-description>
<order-source></order-source>
<order-status>Ready</order-status>
<payor-acct>151915</payor-acct>
<agency-flag>N</agency-flag>
<rate-note></rate-note>
<ad-content>
<b>ATTENTION DIABETICS </b>with Medicare.  Get a FREE Talking Meter and diabetic supplies at NO COST plus FREE home delivery!  Best of all, this meter eliminates painful finger pricking!  Call 1-888-667-5202 (wcan)</ad-content>
</ad-type>

I need to pull the data out of it that I need (not all) and apply formatting. I also don't want any repeating heads. I have accomplished this much with XSL.

What I can't get is the bold tag, within the ad-content tag to show up in the output.

Here is the XSL:

<?xml version="1.0" encoding="ISO-8859-1"?>
<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform">

<xsl:template match="/">
 
<!--Container Element -->
<xsl:element name="ad-type">
 
<!--Start loooping through XML data -->
 <xsl:for-each select="web-export/run-date/pub-code/ad-type">
     
<!--Set up elements. Do not ouput subclass-code and position-description dups-->
<subclass-code>
                  <xsl:value-of select='concat(subclass-code[not(.=preceding::subclass-code)], " ", position-description[not(.=preceding::position-description)])'/>
      </subclass-code>
     
<!--Carriage Return -->
      <xsl:text>&#13;</xsl:text>
     
<!--Add ad content -->
      <ad-content><xsl:value-of select="ad-content"/>
      </ad-content>

<!--Carriage Return -->    
     <xsl:text>&#13;</xsl:text>
     
</xsl:for-each>
</xsl:element>
</xsl:template>      
</xsl:stylesheet>