Error starting at line : 1 in command -
Create or replace procedure zad4(sor VARCHAR2 DEFAULT 'DESC', kol VARCHAR2 DEFAULt 'nr_albumu')
AS
BEGIN
  htp.htmlOpen;
	htp.bodyOpen;
	htp.tableOpen('border="1"');
  Htp.print('Dodaj studenta:<br><form action="http://oracle/pls/id68/zad4_dodaj" method="get">
Nazwisko:<input type="text"  name="nazwisko" size=16>
Imie:<input type="text"  name="imie" size=16>
Wiek:<input type="text"  name="wiek" size=6>
Nr_gr:<input type="text"  name="nr_gr" size=6><br>
<input type="reset" value="RESET" >
<input type="submit" value=" DODAJ " ></form><br><br>');
  Htp.print('Usun studenta:<br><form action="http://oracle/pls/id68/zad4_usun" method="get">
Numer albumu:<input type="text"  name="nr_albumu2" size=16>
Nazwisko:<input type="text"  name="nazwisko2" size=16>
Imie:<input type="text"  name="imie2" size=16>
Wiek:<input type="text"  name="wiek2" size=6>
Nr_gr:<input type="text"  name="nr_gr2" size=6><br>
<input type="reset" value="RESET" >
<input type="submit" value=" USUN " ></form><br><br>');
  Htp.print('Modyfikuj studenta:<br><form action="http://oracle/pls/id68/zad4_edit" method="get">
Numer albumu:<input type="text"  name="nr_albumu2" size=16>
Nazwisko:<input type="text"  name="nazwisko2" size=16>
Imie:<input type="text"  name="imie2" size=16>
Wiek:<input type="text"  name="wiek2" size=6>
Nr_gr:<input type="text"  name="nr_gr2" size=6><br>
Na:
Nazwisko:<input type="text"  name="n_nazwisko" size=16>
Imie:<input type="text"  name="n_imie" size=16>
Wiek:<input type="text"  name="n_wiek" size=6>
Nr_gr:<input type="text"  name="n_nr_gr" size=6><br>
<input type="reset" value="RESET" >
<input type="submit" value=" MODYFIKUJ " ></form><br><br>');
  Htp.print('Sortowanie: <form action="http://oracle/pls/id68/zad4" method="get"><br>
<input type="radio" name="kol"
value="nr_albumu" checked="checked">Numer albumu
<input type="radio" name="kol"
value="nazwisko" checked="checked">Nazwisko
<input type="radio" name="kol"
value="imie" checked="checked">Imie
<input type="radio" name="kol"
value="wiek" checked="checked">Wiek
<input type="radio" name="kol"
value="nr_gr" checked="checked">Numer Grupy <br>

<input type="radio" name="sor"
value="ASC" checked="checked">Rosnaco
<input type="radio" name="sor"
value="DESC" checked="checked">Malejaco
<input type="submit" value=" SORTUJ " ></form><br><br>');

  Htp.print('<tr><td>numer albumu</td><td>nazwisko</td><td>imie</td><td>wiek</td><td>nr grupy</td></tr>');
  owa_util.cellsprint('SELECT * FROM student order by ' || kol || ' ' || sor);
	htp.tableClose;
	htp.bodyClose;
	htp.htmlClose;
END;
Error report -
ORA-00955: name is already used by an existing object
00955. 00000 -  "name is already used by an existing object"
*Cause:
*Action:
PROCEDURE ZAD4_DODAJ compiled
PROCEDURE ZAD4_USUN compiled
PROCEDURE ZAD4_EDIT compiled