wrap text

for node text I am using following template to incert <br/> tag
<xsl:template name="textwrapbb">
	<xsl:param name="Text"/>
<xsl:value-of select="substring(Text, 1, 30)"/>
<br></br>
 <xsl:variable name="rest" select="substring($Text, 31)" />
 <xsl:if test="string-length($rest) &gt; 30">
   <xsl:call-template name="textwrap">
     <xsl:with-param name="Text" select="$rest" />
   </xsl:call-template>
 </xsl:if>
	<xsl:value-of select="$rest"/>
</xsl:template>
</xsl:stylesheet>

My Env. is saxon and java
and it gives following error

java.lang.StackOverflowError
t com.icl.saxon.ContentImpl.appendValue(ContentImpl.java:57)
t com.icl.saxon.ParentNodeImpl.getValue(ParentNodeImpl.java:83)
t com.icl.saxon.expr.NodeSetIntent.asString(NodeSetIntent.java:57)
t com.icl.saxon.functions.Substring.eval(Substring.java:29)
can any one tell me how to use recursive template with saxon parser

or how to do word wrap template .
Thanks
ajrapa