get the oid

Hi list,

I'm not only a novice to pgsql but also to sql in general (as well as
new in this list)...

Here's my question: Why doesn't the following function work?

create function getoid(name) returns integer as '
declare
ret integer;
tablename alias for $1;
begin
select into ret oid from tablename;
return ret;
end;'
language 'plpgsql';

The idea is to get the oid (or whatever) from a table given by its
name as a parameter to the function. It seems that the 'from' clause
can't get the right table when passing a variable with the table
name. I've tried everything to get this to work (castings,
subqueries, etc, etc,...)

Thanx in advance! :-)

Cheers,
Nick