using $1 to filter.

can someone give me a quick example of using the -a argument to procmail to
filter to a specific folder, or based on specific conditions?


i.e.

ARG=$1

:0:
* if $ARG == 'blah'
blah


i've already got sendmail passing the -a argument just fine.

any help/pointers would be appreciated.

-- 
nicholas harteau          the funny thing about regret is..
panic(_at_)construct(_dot_)net         it's better to regret something you have 
done...
panic(_at_)retro(_dot_)geeklab(_dot_)com       than something you haven't.   
-b.s.