HELP: Problems with triggers and sql functions

I am having a problem getting a trigger created and I'm sure it is a
simple/stupid mistake, yet nothing I read, nor nothing I try, seems to let
me create this trigger.

Postgres 6.4 (from the 6.4.1 OOPS distribution) on Linux 2.0.35 SMP.

Sample table tab1:
a b c
xyz stuff here Y
abc more stuff N

Sample table tab2:
l a g
name xyz Y
aname xyz Y

where a is char(16); b is varchar(250); c is char(1); l is char(8); and, g
is char(1).

create function update_tab2 () returns int4 as 'insert into tab2 (l,a,g)
select distinct a.l,b.a,b.c from tab2 a,tab1 b where b.a not in (select
distinct a from tab2); select 1 as exitvalue;' language 'sql';

The function creates properly.

Here's the goal. If and when tab1 has a new value inserted into it, tab2
should be updated according to function update_tab2.

Using the above samples, if I run:
select update_tab2();
I get:
exitvalue
------------
1

and then: select * from tab2;
yields:
l a g
name xyz Y
aname xyz Y
name abc N
aname abc N

which is correct.

So, I try this:

create trigger new_tab1_a after insert on tab1 for each row execute
procedure update_tab2 ();

generates:

ERROR: CreateTrigger: function update_tab2 () does not exist.

I have also tried changing the function and trigger to pass an int4 value.

If I run the function manually, it all works, but I can't get the trigger to
create.

Does anyone have any ideas or advice? This is really frustrating.

Thanks
Greg

Gregory S. Youngblood
ext 2164