can anyone help me...
can u give me any sample for displaying data in drilldown format...
as we click it has to expand...
i tried many times but it is not coming...

You're asking in the wrong place - this is an HTML question, not an XSLT question. Design your (dynamic) HTML first, before you even think about how to write the XSLT code to generate the HTML.

There's all sorts of well-known tricks like using onClick events to change CSS properties from visible to hidden and vice-versa, but they have nothing to do with XSLT.

Michael Kay
http://www.saxonica.com/
Author, XSLT Programmer's Reference and XPath 2.0 Programmer's Reference