public void actionPerformed(ActionEvent e) {
                PreparedStatement st = null;
                try {
                    String sql = "INSERT INTO `Wypożyczenie` VALUES (default, ?, ?, ?, ?, ?, ?, ?, ?)";
                    st = (PreparedStatement) Connect.connection.prepareStatement(sql);
                    st.setDate(1, parseDate(textField_1.getText()));

                    if(textField_2.getText().equals(""))
                        st.setNull(2, Types.TIME);
                    else
                        st.setTime(2, parseTime(textField_2.getText()));

                    st.setDate(3, parseDate(textField_3.getText()));

                    if(textField_4.getText().equals(""))
                        st.setNull(4, Types.TIME);
                    else
                        st.setTime(4, parseTime(textField_4.getText()));

                    if(textField_5.getText().equals("Zakończone"))
                        st.setInt(5, 1);
                    else
                        st.setInt(5, 0);;

                    st.setInt(6, Integer.parseInt(textField_6.getText()));
                    st.setInt(7, Integer.parseInt(textField_7.getText()));
                    st.setInt(8, Integer.parseInt(textField_8.getText()));
                    if((st.executeUpdate()) == 1)
                       {
                           addWypozyczenie();
                           DefaultTableModel model = (DefaultTableModel)wypozyczeniaTable.getModel();
                           model.setRowCount(0);
                           showWypozyczenia();}
                     }
                 catch (Exception ex) {
                        ex.printStackTrace();
                        System.err.println("Got an exception!(insertWypozyczenie) ");
                        System.err.println(ex.getMessage());
                        JFrame frame = new JFrame("Error message");
                        JOptionPane.showMessageDialog(frame, "Zle wpisane dane!");
                            }
                    finally {
                        try {
                            st.close();
                        } catch (SQLException e1) {
                            e1.printStackTrace();
                        }
                    }
                }
        });