> 1.remove element ATTR which ID=11;
> 2.remove item that have no ATTR ID=22.
> 

<xsl:template match="ITEM[ATTR='22']">
  <xsl:copy-of select="@*"/>
  <xsl:apply-templates match="*"/>
</xsl:template>

<xsl:template match="ITEM"/>

<xsl:template match="ATTR[ID='11']"/>

Mike Kay
Software AG

 XSL-List info and archive:  http://www.mulberrytech.com/xsl/xsl-list