private void Button1_Click(object sender, EventArgs e)
        {
            Add_appointment ad = new Add_appointment();

            Close();
            ad.Show();
        }
 private void Button2_Click(object sender, EventArgs e)
 {
     if (dataGridView1.CurrentRow.Index != -1)
     {
         Add_appointment ad = new Add_appointment(Convert.ToInt32(dataGridView1.CurrentRow.Cells[0].Value), Convert.ToInt32(dataGridView1.CurrentRow.Cells[1].Value), Convert.ToDateTime(dataGridView1.CurrentRow.Cells[2].Value), dataGridView1.CurrentRow.Cells[3].Value.ToString());
         Close();
         ad.Show();
     }
 }