private void AddSubject_Click(object sender, EventArgs e)
        {
            string name = FindViewById <EditText>(Resource.Id.dean_newSubject_name).Text;

            if (DataBaseHelper.IsServerAlive())
            {
                DataBaseHelper.AddNewSubgect(name);
                Toast.MakeText(this, "New subject is added!", ToastLength.Long).Show();
            }
            else
            {
                Toast.MakeText(this, "Server isn't alive", ToastLength.Long).Show();
            }
            Finish();
        }
        private void AddProfessor_Click(object sender, EventArgs e)
        {
            string name  = FindViewById <EditText>(Resource.Id.dean_newProfessor_Name).Text;
            int    phone = int.Parse(FindViewById <EditText>(Resource.Id.dean_newProfessor_phone).Text);
            int    room  = int.Parse(FindViewById <EditText>(Resource.Id.dean_newProfessor_room).Text);

            if (DataBaseHelper.IsServerAlive())
            {
                DataBaseHelper.AddNewProfessor(name, phone, room);
                Toast.MakeText(this, "New professor is added!", ToastLength.Long).Show();
            }
            else
            {
                Toast.MakeText(this, "Server isn't alive", ToastLength.Long).Show();
            }
            Finish();
        }
        private void AddStd_Click(object sender, EventArgs e)
        {
            string name    = FindViewById <EditText>(Resource.Id.dean_newStd_Name).Text;
            int    phone   = int.Parse(FindViewById <EditText>(Resource.Id.dean_newStd_Phone).Text);
            int    group   = int.Parse(FindViewById <EditText>(Resource.Id.dean_newStd_GroupNumber).Text);
            int    year    = int.Parse(FindViewById <EditText>(Resource.Id.dean_newStd_StartYear).Text);
            int    groupId = DataBaseHelper.GetGroupIDByNumberAndYear(group, year);

            Toast.MakeText(Application.Context, name + " " + phone + " " + group + " " + year, ToastLength.Long).Show();

            if (DataBaseHelper.IsServerAlive())
            {
                DataBaseHelper.AddNewStudent(name, groupId, phone);
                Toast.MakeText(this, "New student is added!", ToastLength.Long).Show();
            }
            else
            {
                Toast.MakeText(this, "Server isn't alive", ToastLength.Long).Show();
            }
            Finish();
        }
        private void ButtonAddGroup(object sender, EventArgs e)
        {
            int course      = int.Parse(FindViewById <EditText>(Resource.Id.dean_addGroup_Course).Text);
            int groupNumber = int.Parse(FindViewById <EditText>(Resource.Id.dean_addGroup_GroupNumber).Text);
            int year        = int.Parse(FindViewById <EditText>(Resource.Id.dean_addGroup_EntryYear).Text);

            if (DataBaseHelper.IsServerAlive())
            {
                if (DataBaseHelper.GetGroupIDByNumberAndYear(groupNumber, year) == -1)
                {
                    DataBaseHelper.AddNewGroup(course, groupNumber, year);
                    Toast.MakeText(this, "New group is added!", ToastLength.Long).Show();
                }
                else
                {
                    Toast.MakeText(this, "That group is exist already", ToastLength.Long).Show();
                }
            }
            else
            {
                Toast.MakeText(this, "Server isn't alive", ToastLength.Long).Show();
            }
            Finish();
        }