public HttpResponseMessage PostNewAvailableAppointment([FromBody] Available_Appointment newAvailableAppointment)
        {
            try {
                using (Medical_Assistant_System_Entities entities = new Medical_Assistant_System_Entities()) {
                    entities.Available_Appointment.Add(newAvailableAppointment);
                    entities.SaveChanges();

                    var message = Request.CreateResponse(HttpStatusCode.Created, newAvailableAppointment);
                    message.Headers.Location = new Uri(Request.RequestUri + newAvailableAppointment.Id_Available_Appointment.ToString());
                    return(message);
                }
            }
            catch (Exception ex) {
                return(Request.CreateErrorResponse(HttpStatusCode.BadRequest, ex));
            }
        }
        public HttpResponseMessage PutAvailableAppointment(int apointement_id, Available_Appointment availableAppointment)
        {
            try {
                using (Medical_Assistant_System_Entities entities = new Medical_Assistant_System_Entities()){
                    var entity = entities.Available_Appointment.FirstOrDefault(ap => ap.Id_Available_Appointment == apointement_id);

                    if (entity != null)
                    {
                        entity.Available_Time = availableAppointment.Available_Time;
                        entity.Prescriptions  = availableAppointment.Prescriptions;

                        entities.SaveChanges();
                        return(Request.CreateResponse(HttpStatusCode.OK, entity));
                    }
                    else
                    {
                        return(Request.CreateErrorResponse(HttpStatusCode.NotFound, "apointement with id =" + apointement_id.ToString() + " not found to update"));
                    }
                }
            }
            catch (Exception ex) {
                return(Request.CreateErrorResponse(HttpStatusCode.BadRequest, ex));
            }
        }