master.xml

<data>
  <hello>paste your xml here</hello>
  <entry><title message="error"></title></entry>
  <entry><title message="error"></title></entry>
  <entry><title message="error"></title></entry>
  <entry><title message="error"></title></entry>
</data>

master.xsl

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

  <xsl:output method="xml" indent="yes" />

  <xsl:template match="/">
    <hi>
      <xsl:value-of select="data/hello" />
    </hi>
    <xsl:apply-templates select="entry" mode="errors"/>
  </xsl:template>


<xsl:template match="entry" mode="errors">
  <xsl:if test="title/@message = 'error'">
  <xsl:call-template name="error-check">
    <xsl:with-param name="error-count" select="$error-count + 1"/>
    <xsl:if test="position() = last()">
    <xsl:value-of select="$error-count"/>
  </xsl:call-template>
  </xsl:if>
</xsl:template>


<xsl:template name="error-count">
<xsl:param name="error-count" select="0"/>
</xsl:template>
</xsl:stylesheet>