profiling and empty table columns

Hi,

I'm using attributes to control the content of some columns in a table. 
In some versions of the document I'm working on, certain columns won't 
contain any data. Ideally, in these versions, empty columns would be 
removed during processing. For example, in one version of my document, 
the last column is empty. But, the tgroup tag still contains cols='5', 
so the empty column is still in the (html) output - a bunch of empty 
boxes in this case.

I read through the profiling section of "DocBook XSL: The Complete 
Guide" a couple of times and spent some time looking at the various 
children of the table element (in "DocBook: The Definitive Guide"), but 
I haven't been able to find or come up with a way of dealing with this. 
Is there a way to do this in DocBook itself? Do I have to modify the 
stylesheets to do this?

Thanks in advance,

Jeremy Praissman
Department of Biochemistry and Molecular Biology
University of Georgia