Need a Tip to Convert XML Using XSL

I have prepared a XSL file to convert a XML file. The XSL file works for most of the XML nodes. I am stuck in converting one special type of XML node.

Let me show my XML input file and the XSL conversion file below. The node that I seek help is . How do I pick up the value of s:ref?

medicalNotes.xml file:

<?xml version="1.0" encoding="UTF-8"?><feed xmlns="http://www.w3.org/2005/Atom"  xml:base="http://localhost:port/das/"><title type="text">Data Access Service</title><subtitle type="text">Benefits &amp; Health Information Exchange</subtitle><link href="http://localhost:port/das/" rel="self" /><link href="http://localhost:port/das/" rel="alternate" /><entry xml:base="http://localhost:port/dod/"><category term="Consultation Note" /><title type="text">Consultation Note BHIEZZZTESTPATIENT BHIEONE Consultation Note</title><id>DOC_ID_abc123</id><published>2011-07-18T04:00:00.000Z</published><updated>2011-07-18T04:00:00.000Z</updated><author><name>   </name></author><contributor><name>   </name></contributor><content type="application/xml"><Preview xmlns:vler="http://mynamespace.com/schemas/vcp/0.1/health/UnstructuredC62/0.1/subset/vler/" xmlns="" xmlns:s="http://niem.gov/niem/structures/2.0" xmlns:nc="http://niem.gov/niem/niem-core/2.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="unstructuredC62.xsd">
	<nc:Document>
		<nc:DocumentCategoryID>11488-4</nc:DocumentCategoryID>
		<nc:DocumentCategoryText>Consultation Note</nc:DocumentCategoryText>
		<nc:DocumentCreationDate>
			<nc:Date>2011-07-18</nc:Date>
		</nc:DocumentCreationDate>
		<nc:DocumentIdentification>
			<nc:IdentificationID>DOC_ID_abc123</nc:IdentificationID>
			<nc:IdentificationCategoryText>HL7_UD_3.1.4</nc:IdentificationCategoryText>
		</nc:DocumentIdentification>
		<nc:DocumentPublicationDate>
			<nc:Date>2011-07-18</nc:Date>
		</nc:DocumentPublicationDate>
		<nc:DocumentTitleText>BHIEZZZTESTPATIENT BHIEONE Consultation Note</nc:DocumentTitleText>
		<nc:SecurityLevelText>Private</nc:SecurityLevelText>
		<nc:DocumentCoverageTextDate>
			<nc:Date>2011-07-18</nc:Date>
		</nc:DocumentCoverageTextDate>
		<nc:DocumentCoverageTextDate>
			<nc:Date>2011-07-18</nc:Date>
		</nc:DocumentCoverageTextDate>
		<nc:DocumentFormatCategoryText>image/jpeg</nc:DocumentFormatCategoryText>
		<nc:DocumentLanguageCode>mlr</nc:DocumentLanguageCode>
	</nc:Document>
	<vler:Author>
		<vler:TemplateID>1.3.6.1.4.1.19376.1.2.20.1</vler:TemplateID>
		<nc:AssociationBeginDate>
			<nc:Date>2011-07-18</nc:Date>
		</nc:AssociationBeginDate>
		<vler:PersonIdentifier>
			<nc:IdentificationID>XYZ1234</nc:IdentificationID>
			<nc:IdentificationCategoryText>RN License ID</nc:IdentificationCategoryText>
		</vler:PersonIdentifier>
		<nc:RoleOfPersonReference s:ref="ID_Person002"/>
		<nc:ContactInformation>
			<nc:ContactMailingAddress>
				<nc:StructuredAddress>
					<nc:LocationStreet>
						<nc:StreetFullText>10 Hospital Way</nc:StreetFullText>
					</nc:LocationStreet>
					<nc:LocationCityName>Visnville</nc:LocationCityName>
					<nc:LocationStateUSPostalServiceCode>CA</nc:LocationStateUSPostalServiceCode>
					<nc:LocationPostalCode>949877</nc:LocationPostalCode>
				</nc:StructuredAddress>
			</nc:ContactMailingAddress>
			<nc:ContactTelephoneNumber>
				<nc:FullTelephoneNumber>
					<nc:TelephoneNumberFullID>555-555-2345</nc:TelephoneNumberFullID>
				</nc:FullTelephoneNumber>
			</nc:ContactTelephoneNumber>
		</nc:ContactInformation>
		<nc:Organization>
			<nc:OrganizationIdentification>
				<nc:IdentificationID>1.3.5.35.1.4436.7</nc:IdentificationID>
				<nc:IdentificationCategoryText>CDA Root OID</nc:IdentificationCategoryText>
			</nc:OrganizationIdentification>
			<nc:OrganizationName>Visnville VAMC</nc:OrganizationName>
		</nc:Organization>
	</vler:Author>
</Preview></content>
.....
.....

medicalNotes.xsl file:

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="2.0"
	xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
	xmlns="http://gov/va/das/audit"
	xmlns:vler="http://mynamespace.com/schemas/vcp/0.1/health/UnstructuredC62/0.1/subset/vler/"
	xmlns:nc="http://niem.gov/niem/niem-core/2.0"
	xmlns:s="http://niem.gov/niem/structures/2.0"
	xmlns:scr="http://niem.gov/niem/domains/screening/2.1" 	
	xmlns:a="http://www.w3.org/2005/Atom"
	exclude-result-prefixes="vler a nc s scr">

<xsl:output method="xml" indent="yes" omit-xml-declaration="yes"/>
 	<xsl:template match="/">
		<auditableEvents> 
			<xsl:for-each select="a:feed/a:entry">
				 <xsl:variable name="title" select="a:title"/>
				 <xsl:variable name="authorName" select="a:author/a:name"/>
				 <xsl:for-each select="a:content/Preview">
				
				 	<auditableEvent>
						<actionType><xsl:value-of select="$title"/></actionType>
						<createdDate><xsl:value-of select="nc:Document/nc:DocumentCreationDate/nc:Date" /></createdDate>
						<requestingSystem><xsl:value-of select="vler:Author/nc:Organization/nc:OrganizationName" /></requestingSystem>						
						<userId><xsl:value-of select="$authorName"/></userId>
					 </auditableEvent>
				 </xsl:for-each> 
				
			 </xsl:for-each> 		
	</auditableEvents>			 
	</xsl:template>
</xsl:stylesheet>

You use "@" to specify the attributes axis. So in this case "@s:ref" would select that attribute.

Thanks, Paul.