returning a cursor from a function?

[Matthew Hixson <hixson@xxxxxxxxxxxxxxxx>]

I have a create function statement that works with Oracle 8i and I'm  
trying to create this function in Postgres 8.1.2.

CREATE OR REPLACE FUNCTION pr_user( p0 CHAR ) RETURN  
Types.cursor_type IS
rs Types.cursor_type;
BEGIN
OPEN rs FOR
SELECT us.approval_type_code AS us_approval_type_code FROM wbs_users  
us WHERE upper( us.username ) = upper( p0 );
return rs;
END;

Could someone lend me a hand here?
  Thanks in advance,
   -M@