private void AddBT_Click(object sender, EventArgs e) { if (string.IsNullOrEmpty(DescriptionTB.Text) && string.IsNullOrEmpty(ValueTB.Text)) { MessageBox.Show("You need to fill the boxes!"); } else { float value = float.Parse(ValueTB.Text); string date = this.dateTimePicker1.Value.ToString(); string description = DescriptionTB.Text; bm.AddConstantIncome(date, description, value); MessageBox.Show("ConstantIncome is added!"); DescriptionTB.Text = ""; ValueTB.Text = ""; } }