you want to select all control elements that have an item1 and item2
child, so that's

<xsl:for-each select="/tree/controls/control[item1 and item2]">
   <xsl:value-of select="item1/data"/>
   <xsl:value-of select="item2/data"/>
</xsl:for-each>

David

________________________________________________________________________
This e-mail has been scanned for all viruses by Star. The
service is powered by MessageLabs. For more information on a proactive
anti-virus service working around the clock, around the globe, visit:
http://www.star.net.uk
________________________________________________________________________