Clarified Question

Hello,
Earlier I sent in some ramblings trying to explain my problm.
I think I have it better summarised now.

How can I create a function that will take in two variables and return
an integer, when one of the variables is the tablename ?!

I have tried :

create function tst_func(text, varchar(16))
as
'BEGIN
result=select max(history_id)+1 from $1
where client_id = $2;
return result;
END;'

Please excuse the roughness of the code, I am not at my work machine
where I have postgres all setup.

(oh. and jst a little query, is the 'max' actaully a stored procedure
or an SQL keyword ?! I cant seem to find it in any of the documentation
probbly cause I overlooked it ;)

Thanks,
Steffs