private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
{
//MessageBox.Show(comboBox1.selectedValue.ToString());
avail.DoctorID = Convert.ToInt32(comboBox1.SelectedValue.ToString());
avail.Doctor_AvailabilitySearch();
dataGridViewDocAvailability.DataSource = avail.ds.Tables[0];
}