public static void Registration_Booking() { string startDate = ""; string endDate = ""; string hotelID = ""; string guestID = ""; string roomNo = ""; Console.Clear(); System.Console.WriteLine("Please enter following information:"); System.Console.Write("Hotel ID: "); hotelID = System.Console.ReadLine(); System.Console.Write("Room Number: "); roomNo = System.Console.ReadLine(); System.Console.Write("Guest ID: "); guestID = System.Console.ReadLine(); System.Console.Write("Start Date: "); startDate = System.Console.ReadLine(); System.Console.Write("End Date: "); endDate = System.Console.ReadLine(); if (startDate.CompareTo("") == 0 && endDate.CompareTo("") == 0 && hotelID.CompareTo("") == 0 && roomNo.CompareTo("") == 0 && guestID.CompareTo("") == 0) { Console.Clear(); MessageBox.Show("Error: All Input Cannot Empty!", "Error"); return; } try { if (startDate.CompareTo("") != 0 && endDate.CompareTo("") != 0 && hotelID.CompareTo("") != 0 && roomNo.CompareTo("") != 0 && guestID.CompareTo("") != 0) { string sql = "insert into Booking values('" + hotelID + "','" + roomNo + "','" + guestID + "','" + startDate + "','" + endDate + "')"; string booking_reference_num = GenerateRandomNumber(); Loading.Searching_Loading(); if (DataOperation.execSQL(sql)) { System.Console.WriteLine("Data executing successful!"); System.Console.WriteLine("Please waiting..."); Thread.Sleep(2000); System.Console.WriteLine("Thank you!"); System.Console.WriteLine("Your Booking Reference Number is :" + booking_reference_num); System.Console.WriteLine("Press any button to quit!"); System.Console.ReadKey(); Console.Clear(); } else { MessageBox.Show("There is no available room in hotel:\t" + hotelID + "\n time between:\t" + startDate + "\t and \t" + endDate, "Notice"); Console.Clear(); } return; } else { Console.Clear(); MessageBox.Show("Error: All Input Cannot Empty!", "Error"); return; } } catch (Exception e) { Console.Clear(); MessageBox.Show("Error: Wrong!", "Notice"); } }