[xsl] Filtering new tags using XSL

[Buddhi Dananjaya <buddhi@xxxxxxxxxxxxxxxxxxx>]

I have following xml file ( Reduced for clearness - this has more than 
2000):

<root>
   <data name="LBL_MM">
       <value>mm</value>
       <comment>MM</comment>
   </data>
   <data name="LBL_INCH">
       <value>Inches</value>
       <comment>inch</comment>
   </data>
   <data name="DE">
       <value>Drawing Editor</value>
       <comment>DE</comment>
   </data>
   <data name="TO">
       <value>Tray Object</value>
       <comment>TO</comment>
   </data>
</root>

My customer may add new <data></data> blocks into this file, not always 
at the bottom (here and there) can anyone suggest a XSL format ( prefer 
sample code) to filter out  newly added blocks..I need to get a new xml 
file which will contain new <data> blocks after transformation.

- Thanks in advance :-)

- Buddhi from Sri Lanka -