declare
  cursor1;
  cursor2;
begin
  open cursor1;
  loop
    fetch ....
    text_io.put_file('...');
    exit when cursor1%notfound;
  end loop;
  text_io.fclose(file1);
  begin
    open cursor2;
    loop
      fetch ...
      text_io.putfile(..);
      exit when cursor2%notfound;
    end loop;
    text_io.fclose(file2);
    forms_ddl('commit');
  end;
end;

ORA-06502: PL/SQL: numeric or value error string 
Cause: An arithmetic, numeric, string, conversion, or constraint error occurred. 
For example, this error occurs if an attempt is made to assign the value NULL to a variable declared NOT NULL,
or if an attempt is made to assign an integer larger than 99 to a variable declared NUMBER(2). 
Action: Change the data, how it is manipulated, or how it is declared so that values do not violate constraints. 

begin
  open cursor1;
  loop
    fetch ....
    exit when cursor1%notfound;    --> swithc those
    text_io.put_file('...');       --> two lines
  end loop;
  close cursor1;                   --> this is what you've forgotten
  ...

declare
 tcode varchar2(9);
 cursor1;
 cursor2; 
begin
 open cursor1;
  loop
   fetch cursor1 into tcode;
   exit when cursor1%notfound;
   text_io.put_file(tcode);
   end loop;
   fclose(file1);
    begin
     open cursor2;
      loop
       fetch cursor2 into tcode;
        exit when cursor2%notfound;
        text_io.put_line(tcode); 
      end loop;  
      fclose(file2); 
      close cursor1;
      end;
 close cursor2;
 end;

DECLARE
  tCode  VARCHAR2(9);
   
 CurSor1;
 CurSor2;
BEGIN
  OPEN CurSor1;
  
  LOOP
    FETCH CurSor1 INTO tCode;
    
    EXIT WHEN CurSor1%NOTFOUND;
    
    Text_io.Put_File(tCode);
  END LOOP;
  
  fClose(File1);
  
  BEGIN
    OPEN CurSor2;
    
    LOOP
      FETCH CurSor2 INTO tCode;
      
      EXIT WHEN CurSor2%NOTFOUND;
      
      Text_io.Put_Line(tCode);
    END LOOP;
    
    fClose(File2);
    
    CLOSE CurSor1;
  END;
  
  CLOSE CurSor2;
END;