Hi Mike,
  Can you please post this approach in more detail. I am not able to
find anything about it on google.

This solution is likely to be O[n^2] with respect to the number of lines in
the play, which could be rather large. A recursive traversal that uses
apply-templates select="following-sibling::*[1]" would be O[n].

Michael Kay
http://www.saxonica.com/

--
Regards,
Mukul Gandhi