ORACLE - How make PL/SQL cursor with parameter(s)

function CreateInvoice( pNumber varchar2, pErrorMessage out varchar2 ) return number
is
  cursor c_sets( pLief_sch_nr varchar2 ) is
    select * from table
    where
    lief_sch_nr = pLief_sch_nr and
    c_px = 1   
    ;
  pc_sets   c_sets%rowtype;
begin
  ...
  open c_sets( pNumber );
    loop
      fetch c_sets into pc_sets;
      exit when c_sets%notfound;
      ...
    end loop;
  close c_sets;