psqlexception syntax error at or near "$"

In attempting to execute ddl that will create functions I am getting errors
which will not allow the functions to be created. In running with the 8.4
driver if I attempt the following:

CREATE OR REPLACE FUNCTION system_info_fnc01() RETURNS trigger AS
$$
declare
iCnt integer;
begin
select count(*) into iCnt from system_info;
if ( iCnt > 0 ) then
raise exception ''System Info record already present'';
end if;
return new;
end;
$$
LANGUAGE 'plpgsql' IMMUTABLE

I get an error with the $$. In substituting an ' for $$ the following
occurs:
*unterminated quoted string at or near "' declare iCnt integer"*

If I then set the delimiter to something like '|' I still get the
unterminated quote string problem. Could someone tell me how to get around
this problem?

Thanks