private void AddDocumentButton_Click(object sender, EventArgs e) { DataTable dt = MuseumController.GetExhibitsbySerialNumber(Int32.Parse(textBox1.Text)); if (textBox1.Text == "" || textBox3.Text == "" || textBox4.Text == "" || textBox5.Text == "" || textBox2.Text == "") { MessageBox.Show("Please Enter all values!"); } else if (dt != null) { MessageBox.Show("Serial Number is already taken!"); } else if (dt == null) { MuseumController.AddHistoricalDocuments(Int32.Parse(textBox1.Text), dateTimePicker3.Value.ToString("yyyy-MM-dd"), textBox3.Text, dateTimePicker1.Value.ToString("yyyy-MM-dd"), Int32.Parse(textBox4.Text), textBox5.Text, textBox2.Text, Int32.Parse(label28.Text)); MessageBox.Show("Historical Document added successfully!"); } }