given a complicated source XML, I have to change in output the text
element for same nodes mainteinig the source structure.
An example can be this in which I want to change the <elem2> text values.

Well this asks for the identity transformation template
  <xsl:template match="@* | node()">
    <xsl:copy>
      <xsl:apply-templates select="@* | node()"/>
    </xsl:copy>
  </xsl:template>
plus a template for 'elem2' elements e.g.
  <xsl:template match="elem2">
    <xsl:copy>
      <xsl:apply-templates select="@*"/>
      <!-- now put new contents here e.g. -->
      <xsl:value-of select="replace(., 'sub', 'modified')"/>
    </xsl:copy>
  </xsl:template>

	Martin Honnen
	http://JavaScript.FAQTs.com/