Passing a row (NEW) as function argument

Hello all.

First, thanks for all your help in my (silly) last questions. Now I have a
dude about functions that I can't solve with documentation.

How can I pass a row of a view as an argument to function. I have tried
something like:

create function pepis(view_name) returns integer as .../...

but I think it doesn't work, because when I call function from insert rule
of view, I get an error.

I need this for creating views capables of updating and inserting.

Thanks again for your ideas.

David