private void button1_Click(object sender, EventArgs e) { if (textBox1.Text == String.Empty || textBox2.Text == String.Empty) { MessageBox.Show("Please, fill all fields"); return; } try { using (var objProvider = new MailProvider()) { Group objReceiverGroup = objProvider.GetGroupById(iNodeId); if (objReceiverGroup == null) { throw new ArgumentException("Cant find group with current ID: " + iNodeId); } var objReciever = new Receiver(); objReciever.Name = textBox1.Text; objReciever.Email = textBox2.Text; objReciever.Group = objReceiverGroup; objProvider.AddReceiver(objReciever); } this.Close(); } catch (Exception ex) { MessageBox.Show(ex.Message); } }