private void SearchHittingEnterOrButtonClick()
 {
     if (festivalHandler.CheckIfCustomerExists(textBoxPhoneNumber.Text))
     {
         customer = festivalHandler.GetExistingCustomer(textBoxPhoneNumber.Text);
         OpenChildForm(new ChangeBookingChildForm());
     }
     else
     {
         textBoxPhoneNumber.Text           = "";
         labelCustomerDoesNotExist.Visible = true;
         labelCustomerDoesNotExist.Text    = "No booking for that phone number avaliable!\nPlease try again...";
     }
 }
        private void buttonBook_Click(object sender, EventArgs e)
        {
            string firstName    = textBoxFirstName.Text;
            string lastName     = textBoxLastName.Text;
            string phoneNumber  = textBoxPhoneNumber.Text;
            int    ticketAmount = int.Parse(comboBoxTickets.Text);

            if (festivalHandler.CheckIfCustomerExists(phoneNumber) == false)
            {
                customer           = festivalHandler.GetNewCustomer(firstName, lastName, phoneNumber, ticketAmount, theater);
                buttonBook.Enabled = false;
                OpenChildForm(new SuccesfulBookingForm());
            }
            else
            {
                textBoxFirstName.Text         = "";
                textBoxLastName.Text          = "";
                textBoxPhoneNumber.Text       = "";
                checkBoxNo.Checked            = false;
                labelSelectTime.Visible       = false;
                comboBoxSelectTime.Visible    = false;
                pictureBoxFirstName.Visible   = false;
                pictureBoxLastName.Visible    = false;
                pictureBoxPhoneNumber.Visible = false;
                pictureBoxTickets.Visible     = false;
                labelTicketsLeft.Visible      = false;
                labelAmount.Visible           = false;
                labelTheaterNumber.Visible    = false;
                labelTheaterTitle.Visible     = false;
                labelFirstName.Visible        = false;
                textBoxFirstName.Visible      = false;
                labelLastName.Visible         = false;
                textBoxLastName.Visible       = false;
                labelPhoneNumber.Visible      = false;
                textBoxPhoneNumber.Visible    = false;
                buttonBook.Visible            = false;
                labelWheelChair.Visible       = false;
                checkBoxYes.Visible           = false;
                checkBoxNo.Visible            = false;
                labelEnterInfo.Visible        = false;

                labelErrorMessage.Visible = true;
                labelErrorMessage.Text    = "You have previously booked tickets!\nCancel the tickets\nor try again...";
                buttonTryAgain.Visible    = true;
            }
        }