private void AddButton_Click(object sender, EventArgs e) { string name = NameTextBox.Text; string surname = SurnameTextBox.Text; int ph; int.TryParse(PhoneNrTextBox.Text, out ph); string address = AddressTextBox.Text; if (name == null || name.Equals("")) { MessageBox.Show("Fill the name field!", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error); } else if (surname == null || surname.Equals("")) { MessageBox.Show("Fill the surname field!", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error); } else if (address == null || address.Equals("")) { MessageBox.Show("Fill the address field!", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error); } else if (ph.ToString().Length < 9) { MessageBox.Show("Enter correct phone number!", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error); } else { _parent.NewClientCreated(new CLIENTS { C_NAME = name, SURNAME = surname, PHONE_NUMBER = ph, ADRESS = address }); Close(); } }