private void rdoctorbutton_Click(object sender, EventArgs e)
{
doctordataGridView.DataSource = null;
doctordataGridView.Rows.Clear();
List <Doctor> dlist = da.doctordatagrid();
foreach (var item in dlist)
{
doctordataGridView.Rows.Add(item.Name, item.Contactno, item.Designation);
}
doctorsearchbycomboBox.Items.Clear();
doctorsearchbycomboBox.Items.Add("Name");
doctorsearchbycomboBox.Items.Add("Designation");
doctorsearchbycomboBox.Text = "";
doctorsearchtextBox.Text = "";
rtabControl.SelectedTab = rdoctortab;
}