Question about grouping into a table

I am new to XSLT and am experimenting to write a small application. What 
the application does is to transform XML into a table based on  platform 
column type. Even through XML each product and platform entries are in a 
separate row in XML, I want to flatten and display all platforms for a 
product on the same row of the table in rendered HTML. My data looks 
like as follows:
<?xml version="1.0"?>
<!DOCTYPE deliv SYSTEM 
"http://santhi.us.oracle.com:7777/stylesheets/deliv.dtd";>
<?xml-stylesheet type="text/xsl" 
href="http://santhi.us.oracle.com:7777/stylesheets/delivshow.xsl";?>
<deliv>
<delivtable>
<platforms>
<platrow DelivPlatID="60"  Vendor="IBM" PlatformName="AIX" 
Release="4.3.2" />
<platrow DelivPlatID="61"  Vendor="IBM" PlatformName="AIX" 
Release="4.3.3" />
<platrow DelivPlatID="62"  Vendor="IBM" PlatformName="AIX" Release="5L"  />
<platrow DelivPlatID="1"  Vendor="HP" PlatformName="HP-UX" 
Release="10.20"  />
<platrow DelivPlatID="2"  Vendor="HP" PlatformName="HP-UX" 
Release="11.0"  />
<platrow DelivPlatID="3"  Vendor="HP" PlatformName="HP-UX" Release="11i"  />
<platrow DelivPlatID="90"  Vendor="RedHat" PlatformName="Linux" 
Release="6.0"  />
<platrow DelivPlatID="94"  Vendor="RedHat" PlatformName="Linux" 
Release="AS2.1"  />
<platrow DelivPlatID="95"  Vendor="RedHat" PlatformName="Linux" 
Release="ES7"  />
<platrow DelivPlatID="93"  Vendor="RedHat" PlatformName="Linux" 
Release="7.3"  />
<platrow DelivPlatID="91"  Vendor="RedHat" PlatformName="Linux" 
Release="6.2"  />
<platrow DelivPlatID="92"  Vendor="RedHat" PlatformName="Linux" 
Release="7.2"  />
<platrow DelivPlatID="30"  Vendor="HP" PlatformName="Tru64" 
Release="4.0d"  />
<platrow DelivPlatID="31"  Vendor="HP" PlatformName="Tru64" 
Release="5.0a"  />
<platrow DelivPlatID="32"  Vendor="HP" PlatformName="Tru64" 
Release="5.0b"  />
</platforms>

<deliverables>
<delivrow Did="0" ProductId="2" Release="6.0   " PlatID="94" 
CompletionDate="01/01/1994" TargetDate="02/01/1994" TypeOfRelease="FR" 
BaseRelease="4.3.2"  />
<delivrow Did="0" ProductId="10" Release="5.0   " PlatID="95" 
CompletionDate="01/03/1995" TargetDate="02/01/1995" TypeOfRelease="FR" 
BaseRelease="4.3.2" />
<delivrow Did="0" ProductId="46" Release="5.0   " PlatID="62" 
CompletionDate="01/01/1962" TargetDate="02/01/1962" TypeOfRelease="FR" 
BaseRelease="4.3.2" />
<delivrow Did="0" ProductId="123" Release="Env   " PlatID="30" 
CompletionDate="01/01/2030" TargetDate="02/01/2030" TypeOfRelease="FR" 
BaseRelease="4.3.2"  />
<delivrow Did="0" ProductId="123" Release="FAQ   " PlatID="32" 
CompletionDate="01/01/2032" TargetDate="02/01/2032" TypeOfRelease="FR" 
BaseRelease="4.3.2" />
<delivrow Did="0" ProductId="193" Release="5.0   " PlatID="1" 
CompletionDate="01/01/2001" TargetDate="02/01/2001" TypeOfRelease="FR" 
BaseRelease="4.3.2" />
<delivrow Did="0" ProductId="193" Release="5.1   " PlatID="30" 
CompletionDate="01/02/2030" TargetDate="02/01/2030" TypeOfRelease="FR" 
BaseRelease="4.3.2" />
<delivrow Did="0" ProductId="193" Release="4.3   " PlatID="60" 
CompletionDate="01/01/1960" TargetDate="02/01/1960" TypeOfRelease="FR" 
BaseRelease="4.3.2"  />
<delivrow Did="0" ProductId="193" Release="5.1   " PlatID="90" 
CompletionDate="01/01/1990" TargetDate="02/01/1990" TypeOfRelease="FR" 
BaseRelease="4.3.2" />
<delivrow Did="0" ProductId="276" Release="5.0   " PlatID="60" 
CompletionDate="01/01/1960" TargetDate="02/01/1960" TypeOfRelease="FR" 
BaseRelease="4.3.2" />
</deliverables>
</delivtable>
</deliv>

and my stylesheet looks as follows:

............................
............................
<xsl:key name="prodlookup" match="delivrow" use="@ProductId"/>
...........................
..........................
   <table>
   <xsl:variable name="uniqueIds" 
select="//deliv/delivtable/deliverables/delivrow[not(@ProductId=preceding::delivrow/@ProductId)]" 
/>
   <xsl:for-each select="$uniqueIds">
       <xsl:variable name="currentrow" select="."/>
       <xsl:variable name="tmpprodvector" select="key('prodlookup', 
$currentrow/@ProductId)"/>
       <tr>
         <td><xsl:value-of select="$currentrow/@ProductId"/></td>
              <xsl:for-each select="/deliv/delivtable/platforms/platrow" >
              <xsl:sort select="@*[name()=$plat_sortfield]" 
order="{$sortorder}" data-type="{$plat_sortfieldtype}" />
           <xsl:variable name="currentplatrow" select="."/>
           <xsl:for-each select="$tmpprodvector">
                  <xsl:if test="@PlatID != $currentplatrow/@DelivPlatID">
               <td>N/A</td>
              </xsl:if>
                  <xsl:if test="@PlatID = $currentplatrow/@DelivPlatID">
                       <td><xsl:value-of select="@TargetDate"/></td>
              </xsl:if>
               </xsl:for-each>
         </xsl:for-each>
           </tr>
   </xsl:for-each>
   </table>


The above stylesheet shows 30 <td> elements for product with id 123 
whereas i want to show 15 elements with only two relevant dates filled 
properly.  Is there an easier way to do this? Am i missing something here?
Appreciate any inputs on this.
Ramesh


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