I have this XML design:

<root>
   <aaa>
      <bbb>
         <ccc>ABC</ccc>
         <ddd>out1</ddd>
      </bbb>
      <bbb>
         <ccc>DEF</ccc>
         <ddd>out2</ddd>
      </bbb>
   </aaa>
   <aaa>
      <bbb>
         <ccc>ABC</ccc>
         <ddd>out3</ddd>
      </bbb>
   </aaa>
</root>


and I need to generate this xml output:

<root>
   <aaa>
      <ddd>out1</ddd>
      <ddd>out3</ddd>
   </aaa>
   <aaa>
      <ddd>out2</ddd>
   </aaa>
</root>


i'm having a hard time figuring out how to get the value of "ddd" and put them under a common element "aaa" if their value of "ccc" are the same.

Well
you can possibly do something like this to retrieve the first and the second values for the same name tags, respectively.

//root/aaa[1]/ccc[1] ->for the first.

Hope this helps!

ramesh