CREATE USER in side a TRIGGER FUNCTION

Hi
I want to put login and user managment into the database for security 
reasons. I have  a employee table. When I add a person to the employee 
table I want to create them in the database and when I remove a person I 
want to drop the person from the database also.  How do you do it and 
what is wrong the the following code?

shaun

here is the add person trigger.
CREATE FUNCTION insuser () RETURNS TRIGGER AS
'BEGIN       IF NEW.role = ''clerk'' THEN               EXECUTE CREATE USER NEW.login IN GROUP gp_clerk;       ELSIF
NEW.role= ''medic'' THEN               EXECUTE CREATE USER NEW.login IN GROUP gp_medic;       ELSIF NEW.role =
''super''THEN               CREATE USER NEW.login IN GROUP gp_super;                ELSIF NEW.role = ''admin'' THEN
         CREATE USER NEW.login CREATEUSER IN GROUP gp_admin;               ELSIF NEW.role = ''maint'' THEN
CREATE USER NEW.login CREATEUSER IN GROUP gp_maint;       END IF;       RETURN NEW;
 
END;'
LANGUAGE plpgsql;