Stored Procedure Record Updates using For Loops - Postgres 8.1

Hi,

I'm trying to update a record within a for loop and at the point of
updating I get the following syntax error:

ERROR: syntax error at or near "$1"
LINE 1: update $1 set wfstatus='failed'
^
QUERY: update $1 set wfstatus='failed'
CONTEXT: SQL statement in PL/PgSQL function
"workorder_status_integrity_check" near line 13

********** Error **********

ERROR: syntax error at or near "$1"
SQL state: 42601
Context: SQL statement in PL/PgSQL function
"workorder_status_integrity_check" near line 13

Below is the procedure in question using Postgres 8.1:

CREATE OR REPLACE FUNCTION workorder_status_integrity_check() RETURNS
integer AS $$
DECLARE
workorderRecord workorder%ROWTYPE;
declare counter int DEFAULT 0;
BEGIN

FOR workorderRecord IN SELECT * from workorder LOOP

IF workorderRecord.wfstatus = 'canceled' THEN
counter = counter +1;
ELSEIF workorderRecord.wfstatus = 'finished' THEN
counter = counter +1;
ELSE
update workorderRecord set wfstatus='failed';

END IF;
END LOOP;
RETURN counter;
END;
$$ LANGUAGE plpgsql;

Thanks, Patrick