private void btnNext_Click(object sender, EventArgs e)
        {
            bool fields = checkFields(txtICPassport.Text); //check if the fields are empty or not

            if (fields == true)
            {
                bool found = CustChecking(txtICPassport.Text); //Check if the customer id exists in the customers list
                if (found == true)
                {
                    bool tour = TourChecking(cmbBooking.Text); //check the selected value of the tour combo box
                    if (tour == true)
                    {
                        bool hotelCheck = PackHotChecking(cmbBooking.Text); //check the selected value of the hotel combo boxes
                        if (hotelCheck == true)
                        {
                            // using connection class
                            DBConnect myconn = new DBConnect();
                            // appear details of the selected booking
                            gropbxDetails.Visible = true;
                            lblDetails.Text       = $"{myconn.SelectCust(txtICPassport.Text)} Booking Type : \t \t {cmbBooking.Text} \n Tour Package : \t \t \t {cmbLocation.Text} \n Booking Date : \t \t {dateTimePicker1.Value.ToShortDateString()} \n Hotel : \t  {cmbHotel.Text}\n Room:\t {cmbRoom.Text}\n Night : {cmbNight.Text}";
                        }
                    }
                }
            }
        }