Usual rules: tell us what your input is, tell us what output you want; if you tried something and it didn't work, tell us what you tried and tell us how if failed.
I tried to plaster the ceiling yesterday and it didn't work. Can you tell me what I did wrong?
Michael Kay
http://www.saxonica.com/
Author, XSLT Programmer's Reference and XPath 2.0 Programmer's Reference