/// <summary>
        /// przycisk otwiera panel logowania klienta
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void buttonLogIn_Click(object sender, EventArgs e)
        {
            panelContent.Controls.Clear();
            LogInPanel panel = new LogInPanel(this);

            panelContent.Controls.Add(panel);
        }
        /// <summary>
        /// tworzenie nowego konta w bazie
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void buttonSignUp_Click(object sender, EventArgs e)
        {
            CustomerService service = new CustomerService();

            //jesli textBox'y które wartosci w tabeli mają not null są puste to nie spełnia warunku

            if (textBoxSignUpLogin.Text != "" && textBoxSignUpPassword.Text != "" &&
                textBoxSignUpName.Text != "" && textBoxSignUpSurname.Text != "")
            {
                if (checkBoxTerms.Checked == false)
                {
                    MessageBox.Show("You have to agree terms");
                }
                else
                {
                    service.SignUp(textBoxSignUpLogin.Text, textBoxSignUpPassword.Text,
                                   textBoxSignUpName.Text, textBoxSignUpSurname.Text,
                                   dateTimePickerSignUpBirth.Value.ToString("yyyy-MM-dd"), textBoxSignUpEmail.Text,
                                   textBoxSignUpPhone.Text);
                    formMain.panelContent.Controls.Clear();
                    LogInPanel panel = new LogInPanel(formMain);
                    formMain.panelContent.Controls.Add(panel);
                }
            }
            else
            {
                MessageBox.Show("Complete the data");
            }
        }