based on: http://stackoverflow.com/questions/4845660/xsl-how-to-split-strings

    <xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:tridion="http://www.xyz.com/tridion/schemas">

	<xsl:output method="xml" encoding="utf-8" indent="no"/>

	<xsl:template match="tridion:Office/tridion:Telephone/text()" name="split">
		<xsl:param name="pText" select="."/>
		<xsl:if test="string-length($pText)">
			<xsl:if test="not($pText=.)">
				<br />
			</xsl:if>
			<xsl:value-of select="substring-before(concat($pText,','),',')"/>
			<xsl:call-template name="split">
				<xsl:with-param name="pText" select="substring-after($pText, ',')"/>
			</xsl:call-template>
		</xsl:if>
	</xsl:template>			

	<xsl:template match="office" >
		<h5 id="{@id}">
			<a href="#" property="v:name">
				<xsl:value-of select="name/text()"/>
			</a>
		</h5>
		<div xmlns:v="http://rdf.data-vocabulary.org/#" typeof="v:Organization">
			<div>
				<p>
					<div class="addressDetails">

						<xsl:if test="telephone/text()">
							<div class="moreDetails">
								<p>
									<span>
										<xsl:value-of select="utils:Text('Telephone')"/>
									</span>
								</p>
								<p>

									<span class="normalfont" property="v:tel">
										<xsl:value-of select="telephone/text()"/> 

									</span>
								</p>
								<div class="clearfix">
									<xsl:comment></xsl:comment>
								</div>

							</div>
						</xsl:if>
					</div>
				</p>
			</div>

		</div>
	</xsl:template>



</xsl:stylesheet>