Get Reverse String in XSL

  <xsl:template name="reverse">
    <xsl:param name="theString"/>
    <xsl:variable name="thisLength" select="string-length($theString)"/>
    <xsl:choose>
      <xsl:when test="$thisLength = 1">
        <xsl:value-of select="$theString"/>
      </xsl:when>
      <xsl:otherwise>
        <xsl:variable name="restReverse">
          <xsl:call-template name="reverse">
            <xsl:with-param name="theString"
            select="substring($theString, 1, $thisLength -1)"/>
          </xsl:call-template>
        </xsl:variable>
        <xsl:value-of
        select="concat(substring($theString,$thisLength, 1) ,$restReverse)"/>
      </xsl:otherwise>
    </xsl:choose>
  </xsl:template>

  <!--*****************Start Get File Name from URL *****************-->
  <xsl:template name="GetFileName">
    <xsl:param name="inputString"/>
    <xsl:variable name="delimiter">/</xsl:variable>
    <xsl:variable name="xxx">
      <xsl:call-template name="reverse">
        <xsl:with-param name="theString" select="$inputString" />
      </xsl:call-template>
    </xsl:variable>

    <xsl:variable name="zzz">
      <xsl:call-template name="reverse">
        <xsl:with-param name="theString" select="substring-before($xxx,$delimiter)" />
      </xsl:call-template>
    </xsl:variable>

    <xsl:value-of select="substring-before($zzz,'.')"/>
  </xsl:template>
  <!--*****************End Get File Name from URL *****************-->