protected void Button1_Click(object sender, EventArgs e)
        {
            Label8.Text = "";

            try
            {
                if (string.IsNullOrWhiteSpace(TextBox1.Text) || string.IsNullOrWhiteSpace(TextBox2.Text) || string.IsNullOrWhiteSpace(TextBox3.Text) || string.IsNullOrWhiteSpace(TextBox4.Text))
                {
                    throw new Exception("Patient's name and Doctor's name cannot be empty");
                }

                ADODatabaseService adodbs = new ADODatabaseService();

                DataSet result = adodbs.GetAppointment(TextBox1.Text, TextBox2.Text, TextBox3.Text, TextBox4.Text);
                if (result != null)
                {
                    string[] dateTime = result.Tables[0].Rows[0]["Appointment date & time"].ToString().Split(' ');
                    TextBox5.Text = dateTime[0];
                    TextBox6.Text = dateTime[1];
                    TextBox7.Text = result.Tables[0].Rows[0]["Clinic name"].ToString();

                    TextBox1.Enabled = false;
                    TextBox2.Enabled = false;
                    TextBox3.Enabled = false;
                    TextBox4.Enabled = false;
                    TextBox7.Enabled = false;
                }
                else
                {
                    Label8.Text = "Not found";
                }
            }
            catch (Exception ex)
            {
                Label8.Text = ex.Message;
            }
        }