Hey everyone i'm trying to make a basic PLSQL function for a assignment. the code is below 

```
DECLARE
e_child_record_found  exception;
    PRAGMA EXCEPTION_INIT(e_child_record_found, -02292);
v_afd number;

function afdeling_van(p_mnr in MEDEWERKERS.AFD%type)
    RETURN MEDEWERKERS.AFD%type
    IS
    DEPNR MEDEWERKERS.AFD%type;
    BEGIN
    SELECT AFD into DEPNR FROM MEDEWERKERS WHERE AFD = p_mnr;
end afdeling_van;

procedure ontsla_med(p_mnr in MEDEWERKERS.AFD%type)
    IS 
    BEGIN
    DELETE FROM UITVOERINGEN WHERE DOCENT = p_mnr;
    DELETE FROM INSCHRIJVINGEN WHERE CURSIST = p_mnr;
    DELETE FROM MEDEWERKERS WHERE MNR = p_mnr;
end ontsla_med;

procedure neem_med_aan(p_naam in MEDEWERKERS.NAAM%type,
                       p_voorl in MEDEWERKERS.VOORL%type,
                       p_gbdatum in MEDEWERKERS.GBDATUM%type,
                       p_maandsal in MEDEWERKERS.MAANDSAL%type,
                       p_afd in MEDEWERKERS.AFD%type,
                       p_functie in MEDEWEKERS.FUNCTIE%type DEFAULT('NULL'),
                       p_chef in MEDEWERKERS.CHEF%type DEFAULT('NULL'))
IS    
    v_mnr number;
BEGIN
    SELECT max(MNR)into v_mnr FROM MEDEWERKERS;
    v_mnr := v_mnr + 1;
    INSERT INTO MEDEWERKERS(MNR, naam, voorl, functie, chef, gbdatum, maandsal, afd) VALUES(v_mnr,p_naam, p_voorl, p_gbdatum, p_maandsal, p_afd, p_functie, p_chef);
end neem_med_aan;

BEGIN
    ontsla_med(p_mnr => 7900);
    v_afd := afdeling_van(p_mnr => 7369);
    dbms_output.put_line(v_afd);
    neem_med_aan(p_naam => 'Vermeulen',
                 p_voorl => 't',
                 p_gbdatum => '15-02-1961',
                 p_maandsal => 2000,
                 p_afd => 10);
    neem_med_aan(p_naam => 'derks',
                 p_voorl => 'm',
                 p_gbdatum => '05-aug-61',
                 p_maandsal => 2500,
                 p_afd => 30,
                 p_functie => 'Verkoper',
                 p_chef => 7698);
    neem_med_aan(p_naam => 'Martens',
                 p_voorl => 'i',
                 p_gbdatum => '11-05-1956',
                 p_maandsal => 2100,
                 p_afd => 20,
                 p_functie => 'Trainer');
    neem_med_aan(p_naam => 'Verbeek',
                 p_voorl => 'j',
                 p_gbdatum => '12-09-1950',
                 p_maandsal => 2600,
                 p_afd => 30,
                 p_functie => 'verkoper',
                 p_chef => 7782);
exception
when e_child_record_found then --ORA-melding, zelf gedefinieerd
    raise_application_error(-20000,'De medewerker is nog verbonden aan andere gegevens');
when no_data_found then --voorgedefinieerd door Oracle
    raise_application_error(-20000,'Deze medewerker bestaat niet');
end;

```

Now i get the following errors

```
Error report -
ORA-06550: line 27, column 41:
PLS-00201: identifier 'MEDEWEKERS.FUNCTIE' must be declared
ORA-06550: line 22, column 5:
PL/SQL: Item ignored
ORA-06550: line 41, column 9:
PLS-00313: 'NEEM_MED_AAN' not declared in this scope
ORA-06550: line 41, column 9:
PL/SQL: Statement ignored
ORA-06550: line 46, column 9:
PLS-00313: 'NEEM_MED_AAN' not declared in this scope
ORA-06550: line 46, column 9:
PL/SQL: Statement ignored
ORA-06550: line 53, column 9:
PLS-00313: 'NEEM_MED_AAN' not declared in this scope
ORA-06550: line 53, column 9:
PL/SQL: Statement ignored
ORA-06550: line 59, column 9:
PLS-00313: 'NEEM_MED_AAN' not declared in this scope
ORA-06550: line 59, column 9:
PL/SQL: Statement ignored
06550. 00000 -  "line %s, column %s:\n%s"
*Cause:    Usually a PL/SQL compilation error.
*Action:

```

The procedures and function inside the declare were already there so i just added the code inside. Does this have something to do with the code inside? or is something wrong with the procedures placement or something like that. Would love some help, thanks in advance.