private void btAddRoom_Click_1(object sender, EventArgs e) { errorProvider1.Clear(); errorProvider2.Clear(); errorProvider3.Clear(); errorProvider4.Clear(); if (txtNameRoom.Text == "") { errorProvider1.SetError(txtNameRoom, "not null!"); } else if (txtKindRoom.Text == "") { errorProvider2.SetError(txtKindRoom, "not null!"); } else if (txtBedsAmount.Text == "") { errorProvider3.SetError(txtBedsAmount, "not null!"); } else if (txtCost.Text == "") { errorProvider4.SetError(txtCost, "not null!"); } else { rmBus = new RoomBUS(); RoomDTO rm = new RoomDTO(); rm.Idr = txtNameRoom.Text; rm.Name = txtNameRoom.Text; rm.Roomkind = txtKindRoom.Text; rm.Status = "Empty"; rm.Bedamount = int.Parse(txtBedsAmount.Text); rm.Cost = Decimal.Parse(txtCost.Text); bool kq = rmBus.add(rm); if (kq == false) { MessageBox.Show("Fail!"); } else { MessageBox.Show("Sussces"); } this.loadData(); } }