[texhax] Incrementing a counter on a page boundary?

[Adrian F. Clark]

I'm preparing a LaTeX document which involves per-page numbering.  In
other words, I need "1a" "1b" etc on p1, "2a" "2b" etc on p2, and so on.

Thanks to David Kastrup's excellent perpage.sty, I am able to handle
what I thought was the difficult part, the "a", "b" part of the
numbering scheme.  However, I'm struggling to get the page number to
come out right: in particular, \thepage can give a value that is one too
small at the top of a page -- presumably because of the way TeX "cuts
the scroll".  Does anyone have a solution to this, perhaps a variation
on perpage.sty that increments rather than resets a counter?  I'm afraid
the wizardry in perpage.sty is beyond me these days...

Many thanks in advance.

..Adrian
-- 
Dr Adrian F Clark                WEB: http://esewww.essex.ac.uk/~alien/
EMAIL: alien at essex.ac.uk   TEL: +44 1206 872432    FAX: +44 1206 872900
PAPER: VASE Lab, Dept ESE, University of Essex, Colchester, CO4 3SQ, UK