Rules and Views

Can anyone give me a clue as to how to get rules working with views? I
have a large table I call 'sardata' and several views, an example of
which is 'sun_u'. What I want to do is insert data into 'sun_u' and
have it in turn actually update the 'sardata' table. I've looked at the
examples on the postgresql web page but when I try those examples it
complains, saying "Attribute 'usr' not found" with 'usr' being my first
column. Here is a copy of one of my attempts:

create rule ins_sun_u as on insert
sarweb-> to sun_u do instead insert into sardata values ( usr, sys, wio,
idle, time, systemid );
ERROR: Attribute 'usr' not found

Any help would be greatly appreciated.

Thanks,

Travis