SQL & PL/SQL

Hi all,
i have the need to implement an FTP procedure and accordingly to what i found here : http://www.oracle-base.com/articles/misc/ftp-from-plsql.php i try this code:

DECLARE
	l_conn  UTL_TCP.connection;
	l_result  PLS_INTEGER;
BEGIN
	l_conn := UTL_TCP.open_connection('remotehost', '21');
	dbms_output.put_line('1 '||UTL_TCP.get_line(l_conn, TRUE));

	l_result := UTL_TCP.write_line(l_conn, 'USER user');
	dbms_output.put_line('2 '||UTL_TCP.get_line(l_conn, TRUE));

	l_result := UTL_TCP.write_line(l_conn, 'PASS passord');
	dbms_output.put_line('3 '||UTL_TCP.get_line(l_conn, TRUE));

	l_result := UTL_TCP.write_line(l_conn, 'cwd /some/remote/path');
	begin
		loop
		    dbms_output.put_line('4 '||UTL_TCP.get_line(l_conn, TRUE));
		end loop;
	exception
  		when UTL_TCP.END_OF_INPUT then
		    null;
    end;
	l_result := UTL_TCP.write_line(l_conn, 'bye');
	UTL_TCP.close_connection(l_conn);
END;	

in order to intercept all the returning messages ... but the loop never raise exception.

Any suggestion?
Thanks

Alex