I see now that the OP did a repost of his original message and did some 
more updates to clarify his point. For archive readers, the OP restarted 
in this thread: 
http://www.biglist.com/lists/xsl-list/archives/200703/msg00871.html



Abel Braaksma wrote:
Senthilkumaravelan Krishnanatham wrote:
In a XML,if the following sibling of my test node value is "N" and 
that condition comma would not be introduced .

I need to introduce comma between all unique values and based on the 
sibling of the my test node .

Can not always look for the next subsequent following sibling

why not? In XPath you can do this with following-sibling::*[1] or 
similar.



it is based on the list of unique node values and following sibling 
indicator I need to introduce comma if last but one I need to 
introduce "and" alsoo and terminated by period.




I have no idea what you mean by this. In an earlier message you wrote:




My expected out is

<products>1 and 2. 

which I'm afraid is not going to help me much in helping you. You talk 
of a comma, the word "and" and a period on the end, based on a 
'following-sibling' condition, but you fail to say what goes wrong 
with your current code and you did not say what happened after you 
applied my suggestions and how that deviated from your expectations.



-- Abel